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Whaley SG, Berkow EL, Rybak JM, Nishimoto AT, Barker KS, Rogers PD. Azole Antifungal Resistance in Candida albicans and Emerging Non- albicans Candida Species. Front Microbiol 2017; 7:2173. [PMID: 28127295 PMCID: PMC5226953 DOI: 10.3389/fmicb.2016.02173] [Citation(s) in RCA: 410] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/28/2016] [Indexed: 12/15/2022] Open
Abstract
Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species.
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Affiliation(s)
- Sarah G Whaley
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Elizabeth L Berkow
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Jeffrey M Rybak
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Andrew T Nishimoto
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Katherine S Barker
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - P David Rogers
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science CenterMemphis, TN, USA; Center for Pediatric Pharmacokinetics and Therapeutics, University of Tennessee Health Science CenterMemphis, TN, USA
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102
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Hagiwara D, Miura D, Shimizu K, Paul S, Ohba A, Gonoi T, Watanabe A, Kamei K, Shintani T, Moye-Rowley WS, Kawamoto S, Gomi K. A Novel Zn2-Cys6 Transcription Factor AtrR Plays a Key Role in an Azole Resistance Mechanism of Aspergillus fumigatus by Co-regulating cyp51A and cdr1B Expressions. PLoS Pathog 2017; 13:e1006096. [PMID: 28052140 PMCID: PMC5215518 DOI: 10.1371/journal.ppat.1006096] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 11/28/2016] [Indexed: 02/08/2023] Open
Abstract
Successful treatment of aspergillosis caused by Aspergillus fumigatus is threatened by an increasing incidence of drug resistance. This situation is further complicated by the finding that strains resistant to azoles, the major antifungal drugs for aspergillosis, have been widely disseminated across the globe. To elucidate mechanisms underlying azole resistance, we identified a novel transcription factor that is required for normal azole resistance in Aspergillus fungi including A. fumigatus, Aspergillus oryzae, and Aspergillus nidulans. This fungal-specific Zn2-Cys6 type transcription factor AtrR was found to regulate expression of the genes related to ergosterol biosynthesis, including cyp51A that encodes a target protein of azoles. The atrR deletion mutant showed impaired growth under hypoxic conditions and attenuation of virulence in murine infection model for aspergillosis. These results were similar to the phenotypes for a mutant strain lacking SrbA that is also a direct regulator for the cyp51A gene. Notably, AtrR was responsible for the expression of cdr1B that encodes an ABC transporter related to azole resistance, whereas SrbA was not involved in the regulation. Chromatin immunoprecipitation assays indicated that AtrR directly bound both the cyp51A and cdr1B promoters. In the clinically isolated itraconazole resistant strain that harbors a mutant Cyp51A (G54E), deletion of the atrR gene resulted in a hypersensitivity to the azole drugs. Together, our results revealed that AtrR plays a pivotal role in a novel azole resistance mechanism by co-regulating the drug target (Cyp51A) and putative drug efflux pump (Cdr1B).
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Affiliation(s)
- Daisuke Hagiwara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
- * E-mail: (DH); (KG)
| | - Daisuke Miura
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kiminori Shimizu
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Sanjoy Paul
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ayumi Ohba
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Tohru Gonoi
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Akira Watanabe
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Katsuhiko Kamei
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Takahiro Shintani
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - W. Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Susumu Kawamoto
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Katsuya Gomi
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- * E-mail: (DH); (KG)
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103
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Pais P, Pires C, Costa C, Okamoto M, Chibana H, Teixeira MC. Membrane Proteomics Analysis of the Candida glabrata Response to 5-Flucytosine: Unveiling the Role and Regulation of the Drug Efflux Transporters CgFlr1 and CgFlr2. Front Microbiol 2016; 7:2045. [PMID: 28066366 PMCID: PMC5174090 DOI: 10.3389/fmicb.2016.02045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 12/06/2016] [Indexed: 11/19/2022] Open
Abstract
Resistance to 5-flucytosine (5-FC), used as an antifungal drug in combination therapy, compromises its therapeutic action. In this work, the response of the human pathogen Candida glabrata to 5-FC was evaluated at the membrane proteome level, using an iTRAQ-based approach. A total of 32 proteins were found to display significant expression changes in the membrane fraction of cells upon exposure to 5-FC, 50% of which under the control of CgPdr1, the major regulator of azole drug resistance. These proteins cluster into functional groups associated to cell wall assembly, lipid metabolism, amino acid/nucleotide metabolism, ribosome components and translation machinery, mitochondrial function, glucose metabolism, and multidrug resistance transport. Given the obtained indications, the function of the drug:H+ antiporters CgFlr1 (ORF CAGL0H06017g) and CgFlr2 (ORF CAGL0H06039g) was evaluated. The expression of both proteins, localized to the plasma membrane, was found to confer flucytosine resistance. CgFlr2 further confers azole drug resistance. The deletion of CgFLR1 or CgFLR2 was seen to increase the intracellular accumulation of 5-FC, or 5-FC and clotrimazole, suggesting that these transporters play direct roles in drug extrusion. The expression of CgFLR1 and CgFLR2 was found to be controlled by the transcription factors CgPdr1 and CgYap1, major regulator of oxidative stress resistance.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de LisboaLisbon, Portugal; Biological Sciences Research Group, Institute for Bioengineering and Biosciences, Instituto Superior TécnicoLisboa, Portugal
| | - Carla Pires
- Department of Bioengineering, Instituto Superior Técnico, Universidade de LisboaLisbon, Portugal; Biological Sciences Research Group, Institute for Bioengineering and Biosciences, Instituto Superior TécnicoLisboa, Portugal
| | - Catarina Costa
- Department of Bioengineering, Instituto Superior Técnico, Universidade de LisboaLisbon, Portugal; Biological Sciences Research Group, Institute for Bioengineering and Biosciences, Instituto Superior TécnicoLisboa, Portugal
| | - Michiyo Okamoto
- Medical Mycology Research Center, Chiba University Chiba, Japan
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University Chiba, Japan
| | - Miguel C Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de LisboaLisbon, Portugal; Biological Sciences Research Group, Institute for Bioengineering and Biosciences, Instituto Superior TécnicoLisboa, Portugal
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104
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Healey KR, Jimenez Ortigosa C, Shor E, Perlin DS. Genetic Drivers of Multidrug Resistance in Candida glabrata. Front Microbiol 2016; 7:1995. [PMID: 28018323 PMCID: PMC5156712 DOI: 10.3389/fmicb.2016.01995] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/29/2016] [Indexed: 12/31/2022] Open
Abstract
Both the incidence of invasive fungal infections and rates of multidrug resistance associated with fungal pathogen Candida glabrata have increased in recent years. In this perspective, we will discuss the mechanisms underlying the capacity of C. glabrata to rapidly develop resistance to multiple drug classes, including triazoles and echinocandins. We will focus on the extensive genetic diversity among clinical isolates of C. glabrata, which likely enables this yeast to survive multiple stressors, such as immune pressure and antifungal exposure. In particular, over half of C. glabrata clinical strains collected from U.S. and non-U.S. sites have mutations in the DNA mismatch repair gene MSH2, leading to a mutator phenotype and increased frequencies of drug-resistant mutants in vitro. Furthermore, recent studies and data presented here document extensive chromosomal rearrangements among C. glabrata strains, resulting in a large number of distinct karyotypes within a single species. By analyzing clonal, serial isolates derived from individual patients treated with antifungal drugs, we were able to document chromosomal changes occurring in C. glabrata in vivo during the course of antifungal treatment. Interestingly, we also show that both MSH2 genotypes and chromosomal patterns cluster consistently into specific strain types, indicating that C. glabrata has a complex population structure where genomic variants arise, perhaps during the process of adaptation to environmental changes, and persist over time.
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Affiliation(s)
- Kelley R Healey
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School Newark, NJ, USA
| | - Cristina Jimenez Ortigosa
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School Newark, NJ, USA
| | - Erika Shor
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School Newark, NJ, USA
| | - David S Perlin
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School Newark, NJ, USA
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105
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Africa CWJ, Abrantes PMDS. Candida antifungal drug resistance in sub-Saharan African populations: A systematic review. F1000Res 2016; 5:2832. [PMID: 28154753 PMCID: PMC5247777 DOI: 10.12688/f1000research.10327.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/17/2017] [Indexed: 01/16/2023] Open
Abstract
Background:
Candida infections are responsible for increased morbidity and mortality rates in at-risk patients, especially in developing countries where there is limited access to antifungal drugs and a high burden of HIV co-infection.
Objectives: This study aimed to identify antifungal drug resistance patterns within the subcontinent of Africa.
Methods: A literature search was conducted on published studies that employed antifungal susceptibility testing on clinical
Candida isolates from sub-Saharan African countries using Pubmed and Google Scholar.
Results: A total of 21 studies from 8 countries constituted this review. Only studies conducted in sub-Saharan Africa and employing antifungal drug susceptibility testing were included. Regional differences in
Candida species prevalence and resistance patterns were identified.
Discussion: The outcomes of this review highlight the need for a revision of antifungal therapy guidelines in regions most affected by
Candida drug resistance. Better controls in antimicrobial drug distribution and the implementation of regional antimicrobial susceptibility surveillance programmes are required in order to reduce the high
Candida drug resistance levels seen to be emerging in sub-Saharan Africa.
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Affiliation(s)
- Charlene Wilma Joyce Africa
- Microbial Endogenous Infections (MEnIS) Research Laboratories, Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Pedro Miguel Dos Santos Abrantes
- Microbial Endogenous Infections (MEnIS) Research Laboratories, Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
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106
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Proper Sterol Distribution Is Required for Candida albicans Hyphal Formation and Virulence. G3-GENES GENOMES GENETICS 2016; 6:3455-3465. [PMID: 27587298 PMCID: PMC5100844 DOI: 10.1534/g3.116.033969] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Candida albicans is an opportunistic fungus responsible for the majority of systemic fungal infections. Multiple factors contribute to C. albicans pathogenicity. C. albicans strains lacking CaArv1 are avirulent. Arv1 has a conserved Arv1 homology domain (AHD) that has a zinc-binding domain containing two cysteine clusters. Here, we explored the role of the CaAHD and zinc-binding motif in CaArv1-dependent virulence. Overall, we found that the CaAHD was necessary but not sufficient for cells to be virulent, whereas the zinc-binding domain was essential, as Caarv1/Caarv1 cells expressing the full-length zinc-binding domain mutants, Caarv1C3S and Caarv1C28S, were avirulent. Phenotypically, we found a direct correlation between the avirulence of Caarv1/Caarv1, Caarrv1AHD, Caarv1C3S, and Caarv1C28S cells and defects in bud site selection, septa formation and localization, and hyphal formation and elongation. Importantly, all avirulent mutant strains lacked the ability to maintain proper sterol distribution. Overall, our results have established the importance of the AHD and zinc-binding domain in fungal invasion, and have correlated an avirulent phenotype with the inability to maintain proper sterol distribution.
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107
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Gohar AA, Badali H, Shokohi T, Nabili M, Amirrajab N, Moazeni M. Expression Patterns of ABC Transporter Genes in Fluconazole-Resistant Candida glabrata. Mycopathologia 2016; 182:273-284. [PMID: 27744635 DOI: 10.1007/s11046-016-0074-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/29/2016] [Indexed: 11/24/2022]
Abstract
Clinical management of fungal diseases is compromised by the emergence of antifungal drug resistance in fungi, which leads to elimination of available drug classes as treatment options. An understanding of antifungal resistance at molecular level is, therefore, essential for the development of strategies to combat the resistance. This study presents the assessment of molecular mechanisms associated with fluconazole resistance in clinical Candida glabrata isolates originated from Iran. Taking seven distinct fluconazole-resistant C. glabrata isolates, real-time PCRs were performed to evaluate the alternations in the regulation of the genes involved in drug efflux including CgCDR1, CgCDR2, CgSNQ2, and CgERG11. Gain-of-function (GOF) mutations in CgPDR1 alleles were determined by DNA sequencing. Cross-resistance to fluconazole, itraconazole, and voriconazole was observed in 2.5 % of the isolates. In the present study, six amino acid substitutions were identified in CgPdr1, among which W297R, T588A, and F575L were previously reported, whereas D243N, H576Y, and P915R are novel. CgCDR1 overexpression was observed in 57.1 % of resistant isolates. However, CgCDR2 was not co-expressed with CgCDR1. CgSNQ2 was upregulated in 71.4 % of the cases. CgERG11 overexpression does not seem to be associated with azole resistance, except for isolates that exhibited azole cross-resistance. The pattern of efflux pump gene upregulation was associated with GOF mutations observed in CgPDR1. These results showed that drug efflux mediated by adenosine-5-triphosphate (ATP)-binding cassette transporters, especially CgSNQ2 and CgCDR1, is the predominant mechanism of fluconazole resistance in Iranian isolates of C. glabrata. Since some novel GOF mutations were found here, this study also calls for research aimed at investigating other new GOF mutations to reveal the comprehensive understanding about efflux-mediated resistance to azole antifungal agents.
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Affiliation(s)
| | - Hamid Badali
- Invasive Fungi Research Centre, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Tahereh Shokohi
- Invasive Fungi Research Centre, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mojtaba Nabili
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran.,Iranian Social Security Organization, Mazandaran, Iran
| | - Nasrin Amirrajab
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Laboratory Sciences, School of Paramedicine/Infectious and Tropical Diseases Research Centre, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Maryam Moazeni
- Invasive Fungi Research Centre, Mazandaran University of Medical Sciences, Sari, Iran. .,Department of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
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108
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Moazeni M, Kelidari HR, Saeedi M, Morteza-Semnani K, Nabili M, Gohar AA, Akbari J, Lotfali E, Nokhodchi A. Time to overcome fluconazole resistant Candida isolates: Solid lipid nanoparticles as a novel antifungal drug delivery system. Colloids Surf B Biointerfaces 2016; 142:400-407. [DOI: 10.1016/j.colsurfb.2016.03.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 12/25/2022]
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109
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Costa C, Ribeiro J, Miranda IM, Silva-Dias A, Cavalheiro M, Costa-de-Oliveira S, Rodrigues AG, Teixeira MC. Clotrimazole Drug Resistance in Candida glabrata Clinical Isolates Correlates with Increased Expression of the Drug:H(+) Antiporters CgAqr1, CgTpo1_1, CgTpo3, and CgQdr2. Front Microbiol 2016; 7:526. [PMID: 27148215 PMCID: PMC4835504 DOI: 10.3389/fmicb.2016.00526] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/31/2016] [Indexed: 11/13/2022] Open
Abstract
For years, antifungal drug resistance in Candida species has been associated to the expression of ATP-Binding Cassette (ABC) multidrug transporters. More recently, a few drug efflux pumps from the Drug:H(+) Antiporter (DHA) family have also been shown to play a role in this process, although to date only the Candida albicans Mdr1 transporter has been demonstrated to be relevant in the clinical acquisition of antifungal drug resistance. This work provides evidence to suggest the involvement of the C. glabrata DHA transporters CgAqr1, CgQdr2, CgTpo1_1, and CgTpo3 in the clinical acquisition of clotrimazole drug resistance. A screening for azole drug resistance in 138 C. glabrata clinical isolates, from patients attending two major Hospitals in Portugal, was performed. Based on this screening, 10 clotrimazole susceptible and 10 clotrimazole resistant isolates were selected for further analysis. The transcript levels of CgAQR1, CgQDR2, CgTPO1_1, and CgTPO3 were found to be significantly up-regulated in resistant isolates when compared to the susceptible ones, with a level of correlation that was found to be similar to that of CgCDR2, an ABC gene known to be involved in the clinical acquisition of resistance. As a proof-of-concept experiment, the CgTPO3 gene was deleted in an azole resistant C. glabrata isolate, exhibiting high levels of expression of this gene. The deletion of CgTPO3 in this isolate was found to lead to decreased resistance to clotrimazole and fluconazole, and increased accumulation of azole drugs, thus suggesting the involvement of this transporter in the manifestation of azole resistance.
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Affiliation(s)
- Catarina Costa
- Department of Bioengineering, Instituto Superior Técnico, University of LisbonLisboa, Portugal; Institute for Bioengineering and Biosciences, Biological Sciences Research GroupLisboa, Portugal
| | - Jonathan Ribeiro
- Department of Bioengineering, Instituto Superior Técnico, University of LisbonLisboa, Portugal; Institute for Bioengineering and Biosciences, Biological Sciences Research GroupLisboa, Portugal
| | - Isabel M Miranda
- Department of Microbiology, Faculty of Medicine, University of PortoPorto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of PortoPorto, Portugal
| | - Ana Silva-Dias
- Department of Microbiology, Faculty of Medicine, University of PortoPorto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of PortoPorto, Portugal
| | - Mafalda Cavalheiro
- Department of Bioengineering, Instituto Superior Técnico, University of LisbonLisboa, Portugal; Institute for Bioengineering and Biosciences, Biological Sciences Research GroupLisboa, Portugal
| | - Sofia Costa-de-Oliveira
- Department of Microbiology, Faculty of Medicine, University of PortoPorto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of PortoPorto, Portugal
| | - Acácio G Rodrigues
- Department of Microbiology, Faculty of Medicine, University of PortoPorto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of PortoPorto, Portugal
| | - Miguel C Teixeira
- Department of Bioengineering, Instituto Superior Técnico, University of LisbonLisboa, Portugal; Institute for Bioengineering and Biosciences, Biological Sciences Research GroupLisboa, Portugal
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110
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Katiyar S, Shiffrin E, Shelton C, Healey K, Vermitsky JP, Edlind T. Evaluation of Polymorphic Locus Sequence Typing for Candida glabrata Epidemiology. J Clin Microbiol 2016; 54:1042-50. [PMID: 26842706 PMCID: PMC4809956 DOI: 10.1128/jcm.03106-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 01/29/2016] [Indexed: 11/20/2022] Open
Abstract
The opportunistic yeast Candida glabratais increasingly refractory to antifungal treatment or prophylaxis and relatedly is increasingly implicated in health care-associated infections. To elucidate the epidemiology of these infections, strain typing is required. Sequence-based typing provides multiple advantages over length-based methods, such as pulsed-field gel electrophoresis (PFGE); however, conventional multilocus sequence typing (targeting 6 conserved loci) and whole-genome sequencing are impractical for routine use. A commercial sequence-based typing service for C. glabratathat targets polymorphic tandem repeat-containing loci has recently been developed. These CgMT-J and CgMT-M services were evaluated with 56 epidemiologically unrelated isolates, 4 to 7 fluconazole-susceptible or fluconazole-resistant isolates from each of 5 center A patients, 5 matched pairs of fluconazole-susceptible/resistant isolates from center B patients, and 7 isolates from a center C patient who responded to then failed caspofungin therapy. CgMT-J and CgMT-M generated congruent results, resolving isolates into 24 and 20 alleles, respectively. Isolates from all but one of the center A patients shared the same otherwise rare alleles, suggesting nosocomial transmission. Unexpectedly, Pdr1 sequencing showed that resistance arose independently in each patient. Similarly, most isolates from center B also clustered together; however, this may reflect a dominant clone since their alleles were shared by multiple unrelated isolates. Although distinguishable by their echinocandin susceptibilities, all isolates from the center C patient shared alleles, in agreement with the previously reported relatedness of these isolates based on PFGE. Finally, we show how phylogenetic clusters can be used to provide surrogate parents to analyze the mutational basis for antifungal resistance.
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Affiliation(s)
- Santosh Katiyar
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Eric Shiffrin
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Celeste Shelton
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Kelley Healey
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - John-Paul Vermitsky
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Tom Edlind
- MicrobiType LLC, Plymouth Meeting, Pennsylvania, USA
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111
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Kołaczkowska A, Kołaczkowski M. Drug resistance mechanisms and their regulation in non-albicans Candida species. J Antimicrob Chemother 2016; 71:1438-50. [PMID: 26801081 DOI: 10.1093/jac/dkv445] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Fungal pathogens use various mechanisms to survive exposure to drugs. Prolonged treatment very often leads to the stepwise acquisition of resistance. The limited number of antifungal therapeutics and their mostly fungistatic rather than fungicidal character facilitates selection of resistant strains. These are able to cope with cytotoxic molecules by acquisition of appropriate mutations, re-wiring gene expression and metabolic adjustments. Recent evidence points to the paramount importance of the permeability barrier and cell wall integrity in the process of adaptation to high drug concentrations. Molecular details of basal and acquired drug resistance are best characterized in the most frequent human fungal pathogen, Candida albicans Effector genes directly related to the acquisition of elevated tolerance of this species to azole and echinocandin drugs are well described. The emergence of high-level drug resistance against intrinsically lower susceptibility to azoles in yeast species other than C. albicans is, however, of particular concern. This is due to their steadily increasing contribution to high mortality rates associated with disseminated infections. Recent findings concerning underlying mechanisms associated with elevated drug resistance suggest a link to cell wall and plasma membrane metabolism in non-albicans Candida species.
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Affiliation(s)
- Anna Kołaczkowska
- Department of Biochemistry, Pharmacology and Toxicology, Wroclaw University of Environmental and Life Sciences, Norwida 31, PL 50-375, Wroclaw, Poland
| | - Marcin Kołaczkowski
- Department of Biophysics, Wroclaw Medical University, Chalubinskiego 10, PL50-368, Wroclaw, Poland
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112
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Pais P, Costa C, Pires C, Shimizu K, Chibana H, Teixeira MC. Membrane Proteome-Wide Response to the Antifungal Drug Clotrimazole in Candida glabrata: Role of the Transcription Factor CgPdr1 and the Drug:H+ Antiporters CgTpo1_1 and CgTpo1_2. Mol Cell Proteomics 2015; 15:57-72. [PMID: 26512119 DOI: 10.1074/mcp.m114.045344] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Indexed: 01/12/2023] Open
Abstract
Azoles are widely used antifungal drugs. This family of compounds includes triazoles, mostly used in the treatment of systemic infections, and imidazoles, such as clotrimazole, often used in the case of superficial infections. Candida glabrata is the second most common cause of candidemia worldwide and presents higher levels of intrinsic azole resistance when compared with Candida albicans, thus being an interesting subject for the study of azole resistance mechanisms in fungal pathogens.Since resistance often relies on the action of membrane transporters, including drug efflux pumps from the ATP-binding cassette family or from the Drug:H(+) antiporter (DHA)(1) family, an iTRAQ-based membrane proteomics analysis was performed to identify all the membrane-associated proteins whose abundance changes in C. glabrata cells exposed to the azole drug clotrimazole. Proteins found to have significant expression changes in this context were clustered into functional groups, namely: glucose metabolism, oxidative phosphorylation, mitochondrial import, ribosome components and translation machinery, lipid metabolism, multidrug resistance transporters, cell wall assembly, and stress response, comprising a total of 37 proteins. Among these, the DHA transporter CgTpo1_2 (ORF CAGL0E03674g) was identified as overexpressed in the C. glabrata membrane in response to clotrimazole. Functional characterization of this putative drug:H(+) antiporter, and of its homolog CgTpo1_1 (ORF CAGL0G03927g), allowed the identification of these proteins as localized to the plasma membrane and conferring azole drug resistance in this fungal pathogen by actively extruding the drug to the external medium. The cell wall protein CgGas1 was also shown to confer azole drug resistance through cell wall remodeling. Finally, the transcription factor CgPdr1 in the clotrimazole response was observed to control the expression of 20 of the identified proteins, thus highlighting the existence of additional unforeseen targets of this transcription factor, recognized as a major regulator of azole drug resistance in clinical isolates.
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Affiliation(s)
- Pedro Pais
- From the ‡Department of Bioengineering and §IBB-Institute for Bioengineering and Biosciences, Biological Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Catarina Costa
- From the ‡Department of Bioengineering and §IBB-Institute for Bioengineering and Biosciences, Biological Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Carla Pires
- From the ‡Department of Bioengineering and §IBB-Institute for Bioengineering and Biosciences, Biological Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Kiminori Shimizu
- ¶Medical Mycology Research Center (MMRC), Chiba University, Chiba, Japan
| | - Hiroji Chibana
- ¶Medical Mycology Research Center (MMRC), Chiba University, Chiba, Japan
| | - Miguel C Teixeira
- From the ‡Department of Bioengineering and §IBB-Institute for Bioengineering and Biosciences, Biological Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal;
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Costa C, Ponte A, Pais P, Santos R, Cavalheiro M, Yaguchi T, Chibana H, Teixeira MC. New Mechanisms of Flucytosine Resistance in C. glabrata Unveiled by a Chemogenomics Analysis in S. cerevisiae. PLoS One 2015; 10:e0135110. [PMID: 26267134 PMCID: PMC4534419 DOI: 10.1371/journal.pone.0135110] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 07/18/2015] [Indexed: 11/19/2022] Open
Abstract
5-Flucytosine is currently used as an antifungal drug in combination therapy, but fungal pathogens are rapidly able to develop resistance against this drug, compromising its therapeutic action. The understanding of the underlying resistance mechanisms is crucial to deal with this problem. In this work, the S. cerevisiae deletion mutant collection was screened for increased resistance to flucytosine. Through this chemogenomics analysis, 183 genes were found to confer resistance to this antifungal agent. Consistent with its known effect in DNA, RNA and protein synthesis, the most significant Gene Ontology terms over-represented in the list of 5-flucytosine resistance determinants are related to DNA repair, RNA and protein metabolism. Additional functional classes include carbohydrate and nitrogen-particularly arginine-metabolism, lipid metabolism and cell wall remodeling. Based on the results obtained for S. cerevisiae as a model system, further studies were conducted in the pathogenic yeast Candida glabrata. Arginine supplementation was found to relieve the inhibitory effect exerted by 5-flucytosine in C. glabrata. Lyticase susceptibility was found to increase within the first 30min of 5-flucytosine exposure, suggesting this antifungal drug to act as a cell wall damaging agent. Upon exponential growth resumption in the presence of 5-flucytosine, the cell wall exhibited higher resistance to lyticase, suggesting that cell wall remodeling occurs in response to 5-flucytosine. Additionally, the aquaglyceroporin encoding genes CgFPS1 and CgFPS2, from C. glabrata, were identified as determinants of 5-flucytosine resistance. CgFPS1 and CgFPS2 were found to mediate 5-flucytosine resistance, by decreasing 5-flucytosine accumulation in C. glabrata cells.
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Affiliation(s)
- Catarina Costa
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB—Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Andreia Ponte
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB—Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB—Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Rui Santos
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB—Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Mafalda Cavalheiro
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB—Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Takashi Yaguchi
- Medical Mycology Research Center (MMRC), Chiba University, Chiba, Japan
| | - Hiroji Chibana
- Medical Mycology Research Center (MMRC), Chiba University, Chiba, Japan
| | - Miguel Cacho Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB—Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
- * E-mail:
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114
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Shinobu-Mesquita CS, Bonfim-Mendonça PS, Moreira AL, Ferreira ICP, Donatti L, Fiorini A, Svidzinski TIE. Cellular Structural Changes in Candida albicans Caused by the Hydroalcoholic Extract from Sapindus saponaria L. Molecules 2015; 20:9405-18. [PMID: 26007191 PMCID: PMC6272372 DOI: 10.3390/molecules20059405] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 01/27/2015] [Indexed: 01/10/2023] Open
Abstract
Vulvovaginal candidiasis (VVC) is a disease caused by the abnormal growth of yeast-like fungi in the mucosa of the female genital tract. Candida albicans is the principal etiological agent involved in VVC, but reports have shown an increase in the prevalence of Candida non-C. albicans (CNCA) cases, which complicates VVC treatment because CNCA does not respond well to antifungal therapy. Our group has reported the in vitro antifungal activity of extracts from Sapindus saponaria L. The present study used scanning electron microscopy and transmission electron microscopy to further evaluate the antifungal activity of hydroalcoholic extract from S. saponaria (HE) against yeast obtained from VVC and structural changes induced by HE. We observed the antifungal activity of HE against 125 vaginal yeasts that belonged to four different species of the Candida genus and S. cerevisae. The results suggest that saponins that are present in HE act on the cell wall or membrane of yeast at the first moments after contact, causing damage to these structures and cell lysis.
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Affiliation(s)
- Cristiane S Shinobu-Mesquita
- Departamento Análises Clínicas e Biomedicina, Universidade Estadual de Maringá, Av. Colombo 5790, bloco T20, Maringá 87020-900, Brazil.
| | - Patricia S Bonfim-Mendonça
- Departamento Análises Clínicas e Biomedicina, Universidade Estadual de Maringá, Av. Colombo 5790, bloco T20, Maringá 87020-900, Brazil.
| | - Amanda L Moreira
- Departamento de Farmácia, Universidade Estadual de Maringá, Av. Colombo 5790, bloco K80, Maringá 87020-900, Brazil.
| | - Izabel C P Ferreira
- Departamento de Farmácia, Universidade Estadual de Maringá, Av. Colombo 5790, bloco K80, Maringá 87020-900, Brazil.
| | - Lucelia Donatti
- Departamento de Biologia Celular, Universidade Federal do Paraná, Curitiba 85131-990, Brazil.
| | - Adriana Fiorini
- Campus Palotina, Universidade Federal do Paraná, Palotina 85950-000, Brazil.
| | - Terezinha I E Svidzinski
- Departamento Análises Clínicas e Biomedicina, Universidade Estadual de Maringá, Av. Colombo 5790, bloco T20, Maringá 87020-900, Brazil.
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Abstract
Invasive fungal infections remain a major source of global morbidity and mortality, especially among patients with underlying immune suppression. Successful patient management requires antifungal therapy. Yet, treatment choices are restricted due to limited classes of antifungal agents and the emergence of antifungal drug resistance. In some settings, the evolution of multidrug-resistant strains insensitive to several classes of antifungal agents is a major concern. The resistance mechanisms responsible for acquired resistance are well characterized and include changes in drug target affinity and abundance, and reduction in the intracellular level of drug by biofilms and efflux pumps. The development of high-level and multidrug resistance occurs through a stepwise evolution of diverse mechanisms. The genetic factors that influence these mechanisms are emerging and they form a complex symphony of cellular interactions that enable the cell to adapt and/or overcome drug-induced stress. Drivers of resistance involve a complex blend of host and microbial factors. Understanding these mechanisms will facilitate development of better diagnostics and therapeutic strategies to overcome and prevent antifungal resistance.
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Affiliation(s)
- David S Perlin
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, 185 S Orange Ave, Newark, NJ 07103, USA
| | - Erika Shor
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, 185 S Orange Ave, Newark, NJ 07103, USA
| | - Yanan Zhao
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, 185 S Orange Ave, Newark, NJ 07103, USA
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Komatsu A, Satoh T, Wakabayashi H, Ikeda F. Effects of bovine lactoferrin to oral Candida albicans and Candida glabrata isolates recovered from the saliva in elderly people. Odontology 2015; 103:50-55. [PMID: 25756168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effects of bovine lactoferrin (bLF) on the growth of Candida species and on inflammatory cytokine production in gingival keratinocytes, NDUSD-1 co-cultured with Candida strains were investigated. The results showed that bLF at 10 and 100 lg/mL significantly inhibits the growth of two C. albicans strains and two C. glabrata strains isolated from the saliva of elderly people requiring nursing care, respectively. The levels of inflammatory cytokines, interleukin (IL)-6, and IL-8 in NDUSD-1 cocultured with each of these four Candida strains were measured. C. albicans tend to have a more potent capacity than C. glabrata to induce the production of the inflammatory cytokines in NDUSD-1. The levels of IL-6 and IL-8 in NDUSD-1 co-cultured with each of Candida species were measured after addition of bLF. bLF at concentrations from 1 to 100 lg/mL significantly inhibited the production of these cytokines in NDUSD-1 co-cultured with Candida species. These findings suggest that bLF may be useful in reducing the risk of aspiration pneumonia among elderly people requiring care for whom oral care is difficult.
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117
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118
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Cowen LE, Sanglard D, Howard SJ, Rogers PD, Perlin DS. Mechanisms of Antifungal Drug Resistance. Cold Spring Harb Perspect Med 2014; 5:a019752. [PMID: 25384768 DOI: 10.1101/cshperspect.a019752] [Citation(s) in RCA: 336] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Antifungal therapy is a central component of patient management for acute and chronic mycoses. Yet, treatment choices are restricted because of the sparse number of antifungal drug classes. Clinical management of fungal diseases is further compromised by the emergence of antifungal drug resistance, which eliminates available drug classes as treatment options. Once considered a rare occurrence, antifungal drug resistance is on the rise in many high-risk medical centers. Most concerning is the evolution of multidrug- resistant organisms refractory to several different classes of antifungal agents, especially among common Candida species. The mechanisms responsible are mostly shared by both resistant strains displaying inherently reduced susceptibility and those acquiring resistance during therapy. The molecular mechanisms include altered drug affinity and target abundance, reduced intracellular drug levels caused by efflux pumps, and formation of biofilms. New insights into genetic factors regulating these mechanisms, as well as cellular factors important for stress adaptation, provide a foundation to better understand the emergence of antifungal drug resistance.
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Affiliation(s)
- Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Dominique Sanglard
- University of Lausanne and University Hospital Center, Institute of Microbiology, 1011 Lausanne, Switzerland
| | - Susan J Howard
- University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
| | - P David Rogers
- College of Pharmacy, The University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - David S Perlin
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
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119
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Identification of genomic binding sites for Candida glabrata Pdr1 transcription factor in wild-type and ρ0 cells. Antimicrob Agents Chemother 2014; 58:6904-12. [PMID: 25199772 DOI: 10.1128/aac.03921-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The fungal pathogen Candida glabrata is an emerging cause of candidiasis in part owing to its robust ability to acquire tolerance to the major clinical antifungal drug fluconazole. Similar to the related species Candida albicans, C. glabrata most typically gains azole tolerance via transcriptional induction of a suite of resistance genes, including a locus encoding an ABCG-type ATP-binding cassette (ABC) transporter that is referred to as CDR1 in Candida species. In C. glabrata, CDR1 expression is controlled primarily by the activity of a transcriptional activator protein called Pdr1. Strains exhibiting reduced azole susceptibility often contain substitution mutations in PDR1 that in turn lead to elevated mRNA levels of target genes with associated azole resistance. Pdr1 activity is also induced upon loss of the mitochondrial genome status and upon challenge by azole drugs. While extensive analyses of the transcriptional effects of Pdr1 have identified a number of genes that are regulated by this factor, we cannot yet separate direct from indirect target genes. Here we used chromatin immunoprecipitation (ChIP) coupled with high-throughput sequencing (ChIP-seq) to identify the promoters and associated genes directly regulated by Pdr1. These genes include many that are shared with the yeast Saccharomyces cerevisiae but others that are unique to C. glabrata, including the ABC transporter-encoding locus YBT1, genes involved in DNA repair, and several others. These data provide the outline for understanding the primary response genes involved in production of Pdr1-dependent azole resistance in C. glabrata.
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120
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Abstract
Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity.
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Affiliation(s)
- Siobhán A Turner
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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Schwarzmüller T, Ma B, Hiller E, Istel F, Tscherner M, Brunke S, Ames L, Firon A, Green B, Cabral V, Marcet-Houben M, Jacobsen ID, Quintin J, Seider K, Frohner I, Glaser W, Jungwirth H, Bachellier-Bassi S, Chauvel M, Zeidler U, Ferrandon D, Gabaldón T, Hube B, d'Enfert C, Rupp S, Cormack B, Haynes K, Kuchler K. Systematic phenotyping of a large-scale Candida glabrata deletion collection reveals novel antifungal tolerance genes. PLoS Pathog 2014; 10:e1004211. [PMID: 24945925 PMCID: PMC4063973 DOI: 10.1371/journal.ppat.1004211] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 05/13/2014] [Indexed: 11/28/2022] Open
Abstract
The opportunistic fungal pathogen Candida glabrata is a frequent cause of candidiasis, causing infections ranging from superficial to life-threatening disseminated disease. The inherent tolerance of C. glabrata to azole drugs makes this pathogen a serious clinical threat. To identify novel genes implicated in antifungal drug tolerance, we have constructed a large-scale C. glabrata deletion library consisting of 619 unique, individually bar-coded mutant strains, each lacking one specific gene, all together representing almost 12% of the genome. Functional analysis of this library in a series of phenotypic and fitness assays identified numerous genes required for growth of C. glabrata under normal or specific stress conditions, as well as a number of novel genes involved in tolerance to clinically important antifungal drugs such as azoles and echinocandins. We identified 38 deletion strains displaying strongly increased susceptibility to caspofungin, 28 of which encoding proteins that have not previously been linked to echinocandin tolerance. Our results demonstrate the potential of the C. glabrata mutant collection as a valuable resource in functional genomics studies of this important fungal pathogen of humans, and to facilitate the identification of putative novel antifungal drug target and virulence genes. Clinical infections by the yeast-like pathogen Candida glabrata have been ever-increasing over the past years. Importantly, C. glabrata is one of the most prevalent causes of drug-refractory fungal infections in humans. We have generated a novel large-scale collection encompassing 619 bar-coded C. glabrata mutants, each lacking a single gene. Extensive profiling of phenotypes reveals a number of novel genes implicated in tolerance to antifungal drugs that interfere with proper cell wall function, as well as genes affecting fitness of C. glabrata both during normal growth and under environmental stress. This fungal deletion collection will be a valuable resource for the community to study mechanisms of virulence and antifungal drug tolerance in C. glabrata, which is particularly relevant in view of the increasing prevalence of infections caused by this important human fungal pathogen.
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Affiliation(s)
- Tobias Schwarzmüller
- Medical University Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Vienna, Austria
| | - Biao Ma
- Department of Microbiology, Imperial College London, London, United Kingdom
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ekkehard Hiller
- Molekulare Biotechnologie MBT Fraunhofer Institut für Grenzflächen- und Bioverfahrenstechnik IGB Fraunhofer, Stuttgart, Germany
| | - Fabian Istel
- Medical University Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Vienna, Austria
| | - Michael Tscherner
- Medical University Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Vienna, Austria
| | - Sascha Brunke
- Department Microbial Pathogenicity Mechanisms, Hans-Knoell-Institute, Jena, Germany
- Friedrich Schiller University, Jena, Germany
- Center for Sepsis Control and Care, CSCC, Jena University Hospital, Jena, Germany
| | - Lauren Ames
- Department of Microbiology, Imperial College London, London, United Kingdom
- Biosciences, College of Life & Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Arnaud Firon
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Brian Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Vitor Cabral
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Marina Marcet-Houben
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona, Spain
| | - Ilse D. Jacobsen
- Department Microbial Pathogenicity Mechanisms, Hans-Knoell-Institute, Jena, Germany
- Friedrich Schiller University, Jena, Germany
- Center for Sepsis Control and Care, CSCC, Jena University Hospital, Jena, Germany
| | - Jessica Quintin
- UPR 9022 du CNRS, Université de Strasbourg, Equipe Fondation Recherche Médicale, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Katja Seider
- Department Microbial Pathogenicity Mechanisms, Hans-Knoell-Institute, Jena, Germany
| | - Ingrid Frohner
- Medical University Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Vienna, Austria
| | - Walter Glaser
- Medical University Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Vienna, Austria
| | - Helmut Jungwirth
- Institut für Molekulare Biowissenschaften, Universität Graz, Graz, Austria
| | - Sophie Bachellier-Bassi
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
| | - Murielle Chauvel
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
| | - Ute Zeidler
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
| | - Dominique Ferrandon
- UPR 9022 du CNRS, Université de Strasbourg, Equipe Fondation Recherche Médicale, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Bernhard Hube
- Department Microbial Pathogenicity Mechanisms, Hans-Knoell-Institute, Jena, Germany
- Friedrich Schiller University, Jena, Germany
- Center for Sepsis Control and Care, CSCC, Jena University Hospital, Jena, Germany
| | - Christophe d'Enfert
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
- * E-mail: (CE); (SR); (BC); (KH); (KK)
| | - Steffen Rupp
- Molekulare Biotechnologie MBT Fraunhofer Institut für Grenzflächen- und Bioverfahrenstechnik IGB Fraunhofer, Stuttgart, Germany
- * E-mail: (CE); (SR); (BC); (KH); (KK)
| | - Brendan Cormack
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (CE); (SR); (BC); (KH); (KK)
| | - Ken Haynes
- Department of Microbiology, Imperial College London, London, United Kingdom
- Biosciences, College of Life & Environmental Sciences, University of Exeter, Exeter, United Kingdom
- * E-mail: (CE); (SR); (BC); (KH); (KK)
| | - Karl Kuchler
- Medical University Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Vienna, Austria
- * E-mail: (CE); (SR); (BC); (KH); (KK)
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UPC2A is required for high-level azole antifungal resistance in Candida glabrata. Antimicrob Agents Chemother 2014; 58:4543-54. [PMID: 24867980 DOI: 10.1128/aac.02217-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Candida glabrata, the second most common cause of Candida infections, is associated with high rates of mortality and often exhibits resistance to the azole class of antifungal agents. Upc2 and Ecm22 in Saccharomyces cerevisiae and Upc2 in Candida albicans are the transcriptional regulators of ERG11, the gene encoding the target of azoles in the ergosterol biosynthesis pathway. Recently two homologs for these transcription factors, UPC2A and UPC2B, were identified in C. glabrata. One of these, UPC2A, was shown to influence azole susceptibility. We hypothesized that due to the global role for Upc2 in sterol biosynthesis in S. cerevisiae and C. albicans, disruption of UPC2A would enhance the activity of fluconazole in both azole-susceptible dose-dependent (SDD) and -resistant C. glabrata clinical isolates. To test this hypothesis, we constructed mutants with disruptions in UPC2A and UPC2B alone and in combination in a matched pair of clinical azole-SDD and -resistant isolates. Disruption of UPC2A in both the SDD and resistant isolates resulted in increased susceptibility to sterol biosynthesis inhibitors, including a reduction in fluconazole MIC and minimum fungicidal concentration, enhanced azole activity by time-kill analysis, a decrease in ergosterol content, and downregulation of baseline and inducible expression of several sterol biosynthesis genes. Our results indicate that Upc2A is a key regulator of ergosterol biosynthesis and is essential for resistance to sterol biosynthesis inhibitors in C. glabrata. Therefore, the UPC2A pathway may represent a potential cotherapeutic target for enhancing azole activity against this organism.
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Paul S, Moye-Rowley WS. Multidrug resistance in fungi: regulation of transporter-encoding gene expression. Front Physiol 2014; 5:143. [PMID: 24795641 PMCID: PMC3997011 DOI: 10.3389/fphys.2014.00143] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 03/25/2014] [Indexed: 11/24/2022] Open
Abstract
A critical risk to the continued success of antifungal chemotherapy is the acquisition of resistance; a risk exacerbated by the few classes of effective antifungal drugs. Predictably, as the use of these drugs increases in the clinic, more resistant organisms can be isolated from patients. A particularly problematic form of drug resistance that routinely emerges in the major fungal pathogens is known as multidrug resistance. Multidrug resistance refers to the simultaneous acquisition of tolerance to a range of drugs via a limited or even single genetic change. This review will focus on recent progress in understanding pathways of multidrug resistance in fungi including those of most medical relevance. Analyses of multidrug resistance in Saccharomyces cerevisiae have provided the most detailed outline of multidrug resistance in a eukaryotic microorganism. Multidrug resistant isolates of S. cerevisiae typically result from changes in the activity of a pair of related transcription factors that in turn elicit overproduction of several target genes. Chief among these is the ATP-binding cassette (ABC)-encoding gene PDR5. Interestingly, in the medically important Candida species, very similar pathways are involved in acquisition of multidrug resistance. In both C. albicans and C. glabrata, changes in the activity of transcriptional activator proteins elicits overproduction of a protein closely related to S. cerevisiae Pdr5 called Cdr1. The major filamentous fungal pathogen, Aspergillus fumigatus, was previously thought to acquire resistance to azole compounds (the principal antifungal drug class) via alterations in the azole drug target-encoding gene cyp51A. More recent data indicate that pathways in addition to changes in the cyp51A gene are important determinants in A. fumigatus azole resistance. We will discuss findings that suggest azole resistance in A. fumigatus and Candida species may share more mechanistic similarities than previously thought.
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Affiliation(s)
- Sanjoy Paul
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa Iowa City, IA, USA
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa Iowa City, IA, USA
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Phenotypic analysis of a family of transcriptional regulators, the zinc cluster proteins, in the human fungal pathogen Candida glabrata. G3-GENES GENOMES GENETICS 2014; 4:931-40. [PMID: 24657903 PMCID: PMC4025492 DOI: 10.1534/g3.113.010199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Candida glabrata is the second most important human fungal pathogen. Despite its formal name, C. glabrata is in fact more closely related to the nonpathogenic budding yeast Saccharomyces cerevisiae. However, less is known about the biology of this pathogen. Zinc cluster proteins form a large family of transcriptional regulators involved in the regulation of numerous processes such as the control of the metabolism of sugars, amino acids, fatty acids, as well as drug resistance. The C. glabrata genome encodes 41 known or putative zinc cluster proteins, and the majority of them are uncharacterized. We have generated a panel of strains carrying individual deletions of zinc cluster genes. Using a novel approach relying on tetracycline for conditional expression in C. glabrata at the translational level, we show that only two zinc cluster genes are essential. We have performed phenotypic analysis of nonessential zinc cluster genes. Our results show that two deletion strains are thermosensitive whereas two strains are sensitive to caffeine, an inhibitor of the target of rapamycin pathway. Increased salt tolerance has been observed for eight deletion strains, whereas one strain showed reduced tolerance to salt. We have also identified a number of strains with increased susceptibility to the antifungal drugs fluconazole and ketoconazole. Interestingly, one deletion strain showed decreased susceptibility to the antifungal micafungin. In summary, we have assigned phenotypes to more than half of the zinc cluster genes in C. glabrata. Our study provides a resource that will be useful to better understand the biological role of these transcription factors.
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Fonseca E, Silva S, Rodrigues CF, Alves CT, Azeredo J, Henriques M. Effects of fluconazole on Candida glabrata biofilms and its relationship with ABC transporter gene expression. BIOFOULING 2014; 30:447-457. [PMID: 24645630 DOI: 10.1080/08927014.2014.886108] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Candida glabrata has emerged as the second most prevalent fungal pathogen and its ability to form biofilms has been considered one of the most important virulence factors, since biofilms present a high tolerance to antifungal agents used in fungal infection treatment. The mechanisms of biofilm tolerance to antifungal agents remain poorly understood. Thus, the aim of this study was to evaluate the effects of fluconazole (FLU) on the formation and control of C. glabrata biofilms and its relation with the expression of genes encoding for ABC transporters, CDR1, SNQ2, and PDR1. For that, minimal inhibitory concentration values for seven C. glabrata strains were determined and the effect of FLU against C. glabrata biofilms was evaluated by total biomass quantification and viable cell enumeration. Matrices from biofilms were analyzed in terms of protein, carbohydrate and DNA content. ABC transporter gene expression was analyzed for quantitative real-time PCR. In addition to the high amounts of proteins and carbohydrates detected in the extracellular matrices in the presence of FLU, this work showed that the overexpression of efflux pumps is a possible mechanism of biofilm tolerance to FLU and this phenomenon alters the structure of C. glabrata biofilms by creating cell clusters.
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Affiliation(s)
- Elza Fonseca
- a Centre of Biological Engineering (CEB) , University of Minho , Braga , Portugal
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Raghunath P, Seshu Kumari K, Subbannayya K. SST broth, a new serum free germ tube induction medium for identification of Candida albicans. World J Microbiol Biotechnol 2014; 30:1955-8. [PMID: 24497187 DOI: 10.1007/s11274-014-1616-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
Three serum free media viz, sucrose solution, starch solution and SST broth have been formulated. The objective of the present study was to evaluate these three different serum free media for induction of germ tubes by Candida albicans and to compare their efficacy with the pooled human serum. Out of 50 C. albicans isolates 47 (94%) and 49 (98%) produced germ tubes in pooled human serum and SST broth, respectively. Germ tube production was positive in 40 (80%) and 36 (72%) isolates, respectively in sucrose solution and starch solution. This study reports SST broth as a new stable and less expensive germ tube induction medium, which requires less time for preparation and can be used without any safety concerns. SST broth is found to be more effective than pooled human serum for induction of germ tubes by C. albicans isolates.
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Affiliation(s)
- Pendru Raghunath
- Department of Microbiology, Dr. VRK Women's Medical College Teaching Hospital & Research Centre, Aziznagar, R.R. District, Hyderabad, 500075, India,
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Rodrigues CF, Silva S, Henriques M. Candida glabrata: a review of its features and resistance. Eur J Clin Microbiol Infect Dis 2013; 33:673-88. [PMID: 24249283 DOI: 10.1007/s10096-013-2009-3] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/22/2013] [Indexed: 11/30/2022]
Abstract
Candida species belong to the normal microbiota of the oral cavity and gastrointestinal and vaginal tracts, and are responsible for several clinical manifestations, from mucocutaneous overgrowth to bloodstream infections. Once believed to be non-pathogenic, Candida glabrata was rapidly blamable for many human diseases. Year after year, these pathological circumstances are more recurrent and problematic to treat, especially when patients reveal any level of immunosuppression. These difficulties arise from the capacity of C. glabrata to form biofilms and also from its high resistance to traditional antifungal therapies. Thus, this review intends to present an excerpt of the biology, epidemiology, and pathology of C. glabrata, and detail an approach to its resistance mechanisms based on studies carried out up to the present.
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Affiliation(s)
- C F Rodrigues
- IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
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128
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Distinct roles of Candida albicans drug resistance transcription factors TAC1, MRR1, and UPC2 in virulence. EUKARYOTIC CELL 2013; 13:127-42. [PMID: 24243794 DOI: 10.1128/ec.00245-13] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Azoles are widely used in antifungal therapy in medicine. Resistance to azoles can occur in Candida albicans principally by overexpression of multidrug transporter gene CDR1, CDR2, or MDR1 or by overexpression of ERG11, which encodes the azole target. The expression of these genes is controlled by the transcription factors (TFs) TAC1 (involved in the control of CDR1 and CDR2), MRR1 (involved in the control of MDR1), and UPC2 (involved in the control of ERG11). Several gain-of-function (GOF) mutations are present in hyperactive alleles of these TFs, resulting in the overexpression of target genes. While these mutations are beneficial to C. albicans survival in the presence of the antifungal drugs, their effects could potentially alter the fitness and virulence of C. albicans in the absence of the selective drug pressure. In this work, the effect of GOF mutations on C. albicans virulence was addressed in a systemic model of intravenous infection by mouse survival and kidney fungal burden assays. We engineered a set of strains with identical genetic backgrounds in which hyperactive alleles were reintroduced in one or two copies at their genomic loci. The results obtained showed that neither TAC1 nor MRR1 GOF mutations had a significant effect on C. albicans virulence. In contrast, the presence of two hyperactive UPC2 alleles in C. albicans resulted in a significant decrease in virulence, correlating with diminished kidney colonization compared to that by the wild type. In agreement with the effect on virulence, the decreased fitness of an isolate with UPC2 hyperactive alleles was observed in competition experiments with the wild type in vivo but not in vitro. Interestingly, UPC2 hyperactivity delayed filamentation of C. albicans after phagocytosis by murine macrophages, which may at least partially explain the virulence defects. Combining the UPC2 GOF mutation with another hyperactive TF did not compensate for the negative effect of UPC2 on virulence. In conclusion, among the major TFs involved in azole resistance, only UPC2 had a negative impact on virulence and fitness, which may therefore have consequences for the epidemiology of antifungal resistance.
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Antifungal agents commonly used in the superficial and mucosal candidiasis treatment: mode of action and resistance development. Postepy Dermatol Alergol 2013; 30:293-301. [PMID: 24353489 PMCID: PMC3858657 DOI: 10.5114/pdia.2013.38358] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 04/16/2013] [Accepted: 06/23/2013] [Indexed: 12/02/2022] Open
Abstract
Recent progress in medical sciences and therapy resulted in an increased number of immunocompromised individuals. Candida albicans is the leading opportunistic fungal pathogen causing infections in humans, ranging from superficial mucosal lesions to disseminated or bloodstream candidiasis. Superficial candidiasis not always presents a risk to the life of the infected host, however it significantly lowers the quality of life. Superficial Candida infections are difficult to treat and their frequency of occurrence is currently rising. To implement successful treatment doctors should be up to date with better understanding of C. albicans resistance mechanisms. Despite high frequency of Candida infections there is a limited number of antimycotics available for therapy. This review focuses on current understanding of the mode of action and resistance mechanisms to conventional and emerging antifungal agents for treatment of superficial and mucosal candidiasis.
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130
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Yoo JI, Choi CW, Kim HS, Yoo JS, Jeong YH, Lee YS. Proteomic Analysis of Cellular and Membrane Proteins in Fluconazole-Resistant Candida glabrata. Osong Public Health Res Perspect 2013; 3:74-8. [PMID: 24159494 PMCID: PMC3747643 DOI: 10.1016/j.phrp.2012.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 02/15/2012] [Accepted: 02/20/2012] [Indexed: 01/06/2023] Open
Abstract
Objectives Candida glabrata is one of the most common causes of Candida bloodstream infections worldwide. Some isolates of C glabrata may be intermediately resistant to azoles, with some strains developing resistance during therapy or prophylaxis with fluconazole. In this study, we used a proteomic approach to identify differentially expressed proteins between fluconazoleresistant and -susceptible strains. Methods Membrane and cellular proteins were extracted from fluconazolesusceptible and fluconazole-resistant C glabrata strains. Differentially expressed proteins were compared using two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins with >1.5-fold difference in expression were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS). Results A total of 65 proteins were differentially expressed in the cellular and membrane fractions. Among the 39 cellular proteins, 11 were upregulated and 28 were downregulated in fluconazole-resistant strains in comparison with fluconazole-susceptible strains. In the membrane fraction, a total of 26 proteins were found, of which 19 were upregulated and seven were downregulated. A total of 31 proteins were identified by LC-MS/MS that are involved in glycolysis, carbohydrate transport, energy transfer, and other metabolic pathways. Heat shock proteins were identified in various spots. Conclusion Heat shock and stress response proteins were upregulated in the membrane fraction of the fluconazole-resistant C glabrata strain. Compared with susceptible strains, fluconazole-resistant strains showed increased expression of membrane proteins and decreased expression of cellular proteins.
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Affiliation(s)
- Jae Il Yoo
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Chi Won Choi
- Proteome Research Team, Korea Basic Science Institute, Daejeon, Korea
| | - Hwa Su Kim
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Jung Sik Yoo
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Young Hee Jeong
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Yeong Seon Lee
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
- Corresponding author. E-mail:
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Zambuzzi-Carvalho PF, Tomazett PK, Santos SC, Ferri PH, Borges CL, Martins WS, de Almeida Soares CM, Pereira M. Transcriptional profile of Paracoccidioides induced by oenothein B, a potential antifungal agent from the Brazilian Cerrado plant Eugenia uniflora. BMC Microbiol 2013; 13:227. [PMID: 24119145 PMCID: PMC3852496 DOI: 10.1186/1471-2180-13-227] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 10/01/2013] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The compound oenothein B (OenB), which is isolated from the leaves of Eugenia uniflora, a Brazilian Cerrado plant, interferes with Paracoccidioides yeast cell morphology and inhibits 1,3-β-D-glucan synthase (PbFKS1) transcript accumulation, which is involved in cell wall synthesis. In this work we examined the gene expression changes in Paracoccidioides yeast cells following OenB treatment in order to investigate the adaptive cellular responses to drug stress. RESULTS We constructed differential gene expression libraries using Representational Difference Analysis (RDA) of Paracoccidioides yeast cells treated with OenB for 90 and 180 min. Treatment for 90 min resulted in the identification of 463 up-regulated expressed sequences tags (ESTs) and 104 down-regulated ESTs. For the 180 min treatment 301 up-regulated ESTs and 143 down-regulated were identified. Genes involved in the cell wall biosynthesis, such as GLN1, KRE6 and FKS1, were found to be regulated by OenB. Infection experiments in macrophages corroborated the in vitro results. Fluorescence microscopy showed increased levels of chitin in cells treated with OenB. The carbohydrate polymer content of the cell wall of the fungus was also evaluated, and the results corroborated with the transcriptional data. Several other genes, such as those involved in a variety of important cellular processes (i.e., membrane maintenance, stress and virulence) were found to be up-regulated in response to OenB treatment. CONCLUSIONS The exposure of Paracoccidioides to OenB resulted in a complex altered gene expression profile. Some of the changes may represent specific adaptive responses to this compound in this important pathogenic fungus.
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Affiliation(s)
- Patrícia Fernanda Zambuzzi-Carvalho
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICBII, Campus II, Universidade Federal de Goiás, C.P. 131, 74001-970 Goiânia, GO, Brazil
| | - Patrícia Kott Tomazett
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICBII, Campus II, Universidade Federal de Goiás, C.P. 131, 74001-970 Goiânia, GO, Brazil
| | - Suzana Costa Santos
- Laboratório de Bioatividade Molecular, Instituto de Química, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Pedro Henrique Ferri
- Laboratório de Bioatividade Molecular, Instituto de Química, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Clayton Luiz Borges
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICBII, Campus II, Universidade Federal de Goiás, C.P. 131, 74001-970 Goiânia, GO, Brazil
| | | | - Célia Maria de Almeida Soares
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICBII, Campus II, Universidade Federal de Goiás, C.P. 131, 74001-970 Goiânia, GO, Brazil
| | - Maristela Pereira
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICBII, Campus II, Universidade Federal de Goiás, C.P. 131, 74001-970 Goiânia, GO, Brazil
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132
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Yoo JI, Kim HS, Choi CW, Yoo JS, Yu JY, Lee YS. Proteomic Analysis of Intracellular and Membrane Proteins From Voriconazole-Resistant Candida glabrata. Osong Public Health Res Perspect 2013; 4:293-300. [PMID: 24524017 PMCID: PMC3922097 DOI: 10.1016/j.phrp.2013.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 09/30/2013] [Accepted: 10/02/2013] [Indexed: 12/17/2022] Open
Abstract
Objectives The proteomic analysis of voriconazole resistant Candida glabrata strain has not yet been investigated. In this study, differentially expressed proteins of intracellular and membrane fraction from voriconazole-susceptible, susceptible dose-dependent (S-DD), resistant C. glabrata strains were compared with each other and several proteins were identified. Methods The proteins of intracellular and membrane were isolated by disrupting cells with glass bead and centrifugation from voriconazole susceptible, S-DD, and resistant C. glabrata strains. The abundance of expressed proteins was compared using two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis and proteins showing continuous twofold or more increase or reduction of expression in resistant strains compared to susceptible and S-DD strain were analyzed by liquid chromatography/mass spectrometry-mass spectrometry method. Results Of 34 intracellular proteins, 15 proteins showed expression increase or reduction (twofold or more). The identified proteins included regulation, energy production, carbohydrate transport, amino acid transport, and various metabolism related proteins. The increase of expression of heat shock protein 70 was found. Among membrane proteins, 12, 31 proteins showed expression increase or decrease in the order of susceptible, S-DD, and resistant strains. This expression included carbohydrate metabolism, amino acid synthesis, and response to stress-related proteins. In membrane fractions, the change of expression of 10 heat shock proteins was observed, and 9 heat shock protein 70 (Hsp70) showed the reduction of expression. Conclusion The expression of Hsp70 protein in membrane fraction is related to voriconazole resistant C. glabrata strains.
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Affiliation(s)
- Jae Il Yoo
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Hwa Su Kim
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Chi Won Choi
- Proteome Research Team, Korea Basic Science Institute, Daejeon, Korea
| | - Jung Sik Yoo
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Jae Yon Yu
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
| | - Yeong Seon Lee
- Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea
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Contributions of Aspergillus fumigatus ATP-binding cassette transporter proteins to drug resistance and virulence. EUKARYOTIC CELL 2013; 12:1619-28. [PMID: 24123268 DOI: 10.1128/ec.00171-13] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In yeast cells such as those of Saccharomyces cerevisiae, expression of ATP-binding cassette (ABC) transporter proteins has been found to be increased and correlates with a concomitant elevation in azole drug resistance. In this study, we investigated the roles of two Aspergillus fumigatus proteins that share high sequence similarity with S. cerevisiae Pdr5, an ABC transporter protein that is commonly overproduced in azole-resistant isolates in this yeast. The two A. fumigatus genes encoding the ABC transporters sharing the highest sequence similarity to S. cerevisiae Pdr5 are called abcA and abcB here. We constructed deletion alleles of these two different ABC transporter-encoding genes in three different strains of A. fumigatus. Loss of abcB invariably elicited increased azole susceptibility, while abcA disruption alleles had variable phenotypes. Specific antibodies were raised to both AbcA and AbcB proteins. These antisera allowed detection of AbcB in wild-type cells, while AbcA could be visualized only when overproduced from the hspA promoter in A. fumigatus. Overproduction of AbcA also yielded increased azole resistance. Green fluorescent protein fusions were used to provide evidence that both AbcA and AbcB are localized to the plasma membrane in A. fumigatus. Promoter fusions to firefly luciferase suggested that expression of both ABC transporter-encoding genes is inducible by azole challenge. Virulence assays implicated AbcB as a possible factor required for normal pathogenesis. This work provides important new insights into the physiological roles of ABC transporters in this major fungal pathogen.
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Komatsu A, Satoh T, Wakabayashi H, Ikeda F. Effects of bovine lactoferrin to oral Candida albicans and Candida glabrata isolates recovered from the saliva in elderly people. Odontology 2013; 103:50-55. [PMID: 24077721 DOI: 10.1007/s10266-013-0135-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/18/2013] [Indexed: 10/26/2022]
Abstract
The effects of bovine lactoferrin (bLF) on the growth of Candida species and on inflammatory cytokine production in gingival keratinocytes, NDUSD-1 co-cultured with Candida strains were investigated. The results showed that bLF at 10 and 100 μg/mL significantly inhibits the growth of two C. albicans strains and two C. glabrata strains isolated from the saliva of elderly people requiring nursing care, respectively. The levels of inflammatory cytokines, interleukin (IL)-6, and IL-8 in NDUSD-1 co-cultured with each of these four Candida strains were measured. C. albicans tend to have a more potent capacity than C. glabrata to induce the production of the inflammatory cytokines in NDUSD-1. The levels of IL-6 and IL-8 in NDUSD-1 co-cultured with each of Candida species were measured after addition of bLF. bLF at concentrations from 1 to 100 μg/mL significantly inhibited the production of these cytokines in NDUSD-1 co-cultured with Candida species. These findings suggest that bLF may be useful in reducing the risk of aspiration pneumonia among elderly people requiring care for whom oral care is difficult.
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Affiliation(s)
- Akino Komatsu
- Department of Oral and Maxillofacial Surgery, The Nippon Dental University School of Life Dentistry at Tokyo, 1-9-20 Fujimi, Chiyoda-ku, Tokyo, Japan,
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Culakova H, Dzugasova V, Perzelova J, Gbelska Y, Subik J. Mutation of the CgPDR16 gene attenuates azole tolerance and biofilm production in pathogenic Candida glabrata. Yeast 2013; 30:403-14. [PMID: 23939632 DOI: 10.1002/yea.2978] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/23/2013] [Accepted: 08/07/2013] [Indexed: 01/26/2023] Open
Abstract
The PDR16 gene encodes the homologue of Sec14p, participating in protein secretion, regulation of lipid synthesis and turnover in vivo and acting as a phosphatidylinositol transfer protein in vitro. This gene is also involved in the regulation of multidrug resistance in Saccharomyces cerevisiae and pathogenic yeasts. Here we report the results of functional analysis of the CgPDR16 gene, whose mutation has been previously shown to enhance fluconazole sensitivity in Candida glabrata mutant cells. We have cloned the CgPDR16 gene, which was able to complement the pdr16Δ mutation in both C. glabrata and S. cerevisiae. Along with fluconazole, the pdr16Δ mutation resulted in increased susceptibility of mutant cells to several azole antifungals without changes in sensitivity to polyene antibiotics, cycloheximide, NQO, 5-fluorocytosine and oxidants inducing the intracellular formation of reactive oxygen species. The susceptibility of the pdr16Δ mutant strain to itraconazole and 5-fluorocytosine was enhanced by CTBT [7-chlorotetrazolo(5,1-c)benzo(1,2,4)triazine] inducing oxidative stress. The pdr16Δ mutation increased the accumulation of rhodamine 6G in mutant cells, decreased the level of itraconazole resistance caused by gain-of-function mutations in the CgPDR1 gene, and reduced cell surface hydrophobicity and biofilm production. These results point to the pleiotropic phenotype of the pdr16Δ mutant and support the role of the CgPDR16 gene in the control of drug susceptibility and virulence in the pathogenic C. glabrata.
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Affiliation(s)
- Hana Culakova
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic
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Flucytosine antagonism of azole activity versus Candida glabrata: role of transcription factor Pdr1 and multidrug transporter Cdr1. Antimicrob Agents Chemother 2013; 57:5543-7. [PMID: 23979762 DOI: 10.1128/aac.02394-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Infections with the opportunistic yeast Candida glabrata have increased dramatically in recent years. Antifungal therapy of yeast infections commonly employs azoles, such as fluconazole (FLC), but C. glabrata frequently develops resistance to these inhibitors of ergosterol biosynthesis. The pyrimidine analog flucytosine (5-fluorocytosine [5FC]) is highly active versus C. glabrata but is now rarely used clinically due to similar concerns over resistance and, a related concern, the toxicity associated with high doses used to counter resistance. Azole-5FC combination therapy would potentially address these concerns; however, previous studies suggest that 5FC may antagonize azole activity versus C. glabrata. Here, we report that 5FC at subinhibitory concentrations antagonized the activity of FLC 4- to 16-fold versus 8 of 8 C. glabrata isolates tested. 5FC antagonized the activity of other azoles similarly but had only indifferent effects in combination with unrelated antifungals. Since azole resistance in C. glabrata results from transcription factor Pdr1-dependent upregulation of the multidrug transporter gene CDR1, we reasoned that 5FC antagonism might be similarly mediated. Indeed, 5FC-FLC antagonism was abrogated in pdr1Δ and cdr1Δ strains. In further support of this hypothesis, 5FC exposure induced CDR1 expression 6-fold, and this upregulation was Pdr1 dependent. In contrast to azoles, 5FC is not a Cdr1 substrate and so its activation of Pdr1 was unexpected. We observed, however, that 5FC exposure readily induced petite mutants, which exhibit Pdr1-dependent CDR1 upregulation. Thus, mitochondrial dysfunction resulting in Pdr1 activation is the likely basis for 5FC antagonism of azole activity versus C. glabrata.
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Spampinato C, Leonardi D. Candida infections, causes, targets, and resistance mechanisms: traditional and alternative antifungal agents. BIOMED RESEARCH INTERNATIONAL 2013; 2013:204237. [PMID: 23878798 PMCID: PMC3708393 DOI: 10.1155/2013/204237] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/06/2013] [Accepted: 06/06/2013] [Indexed: 11/25/2022]
Abstract
The genus Candida includes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised. Candida infections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genus Candida and yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment of Candida infections is also provided.
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Affiliation(s)
- Claudia Spampinato
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI, UNR-CONICET), Suipacha 531, 2000 Rosario, Argentina
| | - Darío Leonardi
- Departamento de Tecnología Farmacéutica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
- Instituto de Química Rosario (IQUIR, UNR-CONICET), Suipacha 531, 2000 Rosario, Argentina
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Filippidi A, Galanakis E, Maraki S, Galani I, Drogari-Apiranthitou M, Kalmanti M, Mantadakis E, Samonis G. The effect of maternal flora onCandidacolonisation in the neonate. Mycoses 2013; 57:43-8. [DOI: 10.1111/myc.12100] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 05/10/2013] [Accepted: 05/11/2013] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Sofia Maraki
- Department of Microbiology; Heraklion University Hospital; Heraklion Greece
| | - Irene Galani
- Infectious Diseases Research Laboratory; 4th Department of Internal Medicine; National and Kapodistrian University of Athens; Athens Greece
| | - Maria Drogari-Apiranthitou
- Infectious Diseases Research Laboratory; 4th Department of Internal Medicine; National and Kapodistrian University of Athens; Athens Greece
| | - Maria Kalmanti
- Departments of Paediatrics; University of Crete; Heraklion Greece
| | - Elpis Mantadakis
- Department of Paediatrics; Democritus University of Thrace; Alexandroupolis Greece
| | - George Samonis
- Department of Internal Medicine; University of Crete; Heraklion Greece
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139
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Orta-Zavalza E, Guerrero-Serrano G, Gutiérrez-Escobedo G, Cañas-Villamar I, Juárez-Cepeda J, Castaño I, De Las Peñas A. Local silencing controls the oxidative stress response and the multidrug resistance in Candida glabrata. Mol Microbiol 2013; 88:1135-48. [PMID: 23651300 DOI: 10.1111/mmi.12247] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2013] [Indexed: 01/03/2023]
Abstract
In Candida glabrata, the sirtuins Sir2 and Hst1 control the expression of a wide number of genes including adhesins required for host colonization and niacin transporters needed for growth. Given that these sirtuins can be inactivated during infection, we asked if their inhibition could modify the response of C. glabrata to other stressful conditions. Here, we found that deletion of HST1 decreases susceptibility of C. glabrata to fluconazole and hydrogen peroxide. The transcription factor Pdr1 and the ABC transporter Cdr1 mediated the fluconazole resistance phenotype of the hst1Δ cells, whereas the transcriptional activator Msn4 and the catalase Cta1 are necessary to provide oxidative stress resistance. We show that the transcription factor Sum1 interacts with Hst1 and participate in the regulation of these genes. Interestingly, even though C. glabrata and Saccharomyces cerevisiae are closely related phylogenetically, deletion of HST1 decreased susceptibility to fluconazole and hydrogen peroxide only in C. glabrata but not in S. cerevisiae, indicating a different transcriptional control by two similar sirtuins. Our findings suggest that Hst1 acts as a regulator of stress resistance associated-genes.
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Affiliation(s)
- Emmanuel Orta-Zavalza
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Lomas 4a sección, San Luis Potosí, 78216, México
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140
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Candida glabrata drug:H+ antiporter CgQdr2 confers imidazole drug resistance, being activated by transcription factor CgPdr1. Antimicrob Agents Chemother 2013; 57:3159-67. [PMID: 23629708 DOI: 10.1128/aac.00811-12] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The widespread emergence of antifungal drug resistance poses a severe clinical problem. Though predicted to play a role in this phenomenon, the drug:H(+) antiporters (DHA) of the major facilitator superfamily have largely escaped characterization in pathogenic yeasts. This work describes the first DHA from the pathogenic yeast Candida glabrata reported to be involved in antifungal drug resistance, the C. glabrata QDR2 (CgQDR2) gene (ORF CAGL0G08624g). The expression of CgQDR2 in C. glabrata was found to confer resistance to the antifungal drugs miconazole, tioconazole, clotrimazole, and ketoconazole. By use of a green fluorescent protein (GFP) fusion, the CgQdr2 protein was found to be targeted to the plasma membrane in C. glabrata. In agreement with these observations, CgQDR2 expression was found to decrease the intracellular accumulation of radiolabeled clotrimazole in C. glabrata and to play a role in the extrusion of this antifungal from preloaded cells. Interestingly, the functional heterologous expression of CgQDR2 in the model yeast Saccharomyces cerevisiae further confirmed the role of this gene as a multidrug resistance determinant: its expression was able to complement the susceptibility phenotype exhibited by its S. cerevisiae homologue, QDR2, in the presence of imidazoles and of the antimalarial and antiarrhythmic drug quinidine. In contrast to the findings reported for Qdr2, CgQdr2 expression does not contribute to the ability of yeast to grow under K(+)-limiting conditions. Interestingly, CgQDR2 transcript levels were seen to be upregulated in C. glabrata cells challenged with clotrimazole or quinidine. This upregulation was found to depend directly on the transcription factor CgPdr1, the major regulator of multidrug resistance in this pathogenic yeast, which has also been found to be a determinant of quinidine and clotrimazole resistance in C. glabrata.
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141
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Samaranayake YH, Cheung BPK, Wang Y, Yau JYY, Yeung KWS, Samaranayake LP. Fluconazole resistance in Candida glabrata is associated with increased bud formation and metallothionein production. J Med Microbiol 2013; 62:303-318. [DOI: 10.1099/jmm.0.044123-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Y. H. Samaranayake
- Oral Bio-sciences, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR
| | - B. P. K. Cheung
- Oral Bio-sciences, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR
| | - Y. Wang
- Department of Pharmacology and Pharmacy, University of Hong Kong, Hong Kong SAR
| | - J. Y. Y. Yau
- Oral Bio-sciences, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR
| | - K. W. S. Yeung
- Oral Bio-sciences, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR
| | - L. P. Samaranayake
- Oral Bio-sciences, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR
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142
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Balazfyova Z, Hervay NT, Gbelska Y. Gain-of-function mutation in the KlPDR1 gene encoding multidrug resistance regulator in Kluyveromyces lactis. Yeast 2013; 30:71-80. [PMID: 23361926 DOI: 10.1002/yea.2941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/28/2012] [Indexed: 11/10/2022] Open
Abstract
KlPdr1p is a single Kluyveromyces lactis homologue of Saccharomyces cerevisiae ScPdr1p/ScPdr3p, the main transcriptional regulators of genes involved in S. cerevisiae multidrug resistance. KlPDR1 deletion leads to a sharp increase in K. lactis drug susceptibility. The presence of putative PDRE and YRE regulatory elements in the KlPDR1 gene promoter suggests an autoregulation of its transcription as well as its control by KlYap1p, the transcription factor involved in oxidative stress response. In this study, one plasmid-borne Klpdr1-1 allele that led to amino acid substitution (L273P) in the KlPdr1p was isolated. Overexpression of the Klpdr1-1 allele from a multicopy plasmid in the K. lactis wild-type and Klpdr1Δ mutant strain increased the tolerance of transformants to oligomycin. The plasmid-borne Klpdr1-1 allele increased the activation of the ScPDR5 promoter and complemented the drug hypersensitivity of the S. cerevisiae pdr1Δ pdr3Δ mutant strain. The results indicate that L273P amino acid substitution is the result of a gain-of-function mutation in the KlPDR1 gene that confers KlPdr1p hyperactivity, as revealed by a high expression of the ABC transporter gene KlPDR5, leading to multidrug resistance and rhodamine 6G efflux out of the cells.
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Affiliation(s)
- Zuzana Balazfyova
- Department of Microbiology and Virology, Comenius University in Bratislava, Slovak Republic
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143
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Xu N, Liu L, Zou W, Liu J, Hua Q, Chen J. Reconstruction and analysis of the genome-scale metabolic network of Candida glabrata. ACTA ACUST UNITED AC 2013; 9:205-16. [DOI: 10.1039/c2mb25311a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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144
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STB5 is a negative regulator of azole resistance in Candida glabrata. Antimicrob Agents Chemother 2012; 57:959-67. [PMID: 23229483 DOI: 10.1128/aac.01278-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The opportunistic yeast pathogen Candida glabrata is recognized for its ability to acquire resistance during prolonged treatment with azole antifungals (J. E. Bennett, K. Izumikawa, and K. A. Marr. Antimicrob. Agents Chemother. 48:1773-1777, 2004). Resistance to azoles is largely mediated by the transcription factor PDR1, resulting in the upregulation of ATP-binding cassette (ABC) transporter proteins and drug efflux. Studies in the related yeast Saccharomyces cerevisiae have shown that Pdr1p forms a heterodimer with another transcription factor, Stb5p. In C. glabrata, the open reading frame (ORF) designated CAGL0I02552g has 38.8% amino acid identity with STB5 (YHR178w) and shares an N-terminal Zn(2)Cys(6) binuclear cluster domain and a fungus-specific transcriptional factor domain, prompting us to test for homologous function and a possible role in azole resistance. Complementation of a Δyhr178w (Δstb5) mutant with CAGL0I02552g resolved the increased sensitivity to cold, hydrogen peroxide, and caffeine of the mutant, for which reason we designated CAGl0I02552g CgSTB5. Overexpression of CgSTB5 in C. glabrata repressed azole resistance, whereas deletion of CgSTB5 caused a modest increase in resistance. Expression analysis found that CgSTB5 shares many transcriptional targets with CgPDR1 but, unlike the latter, is a negative regulator of pleiotropic drug resistance, including the ABC transporter genes CDR1, PDH1, and YOR1.
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145
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Fks1 and Fks2 are functionally redundant but differentially regulated in Candida glabrata: implications for echinocandin resistance. Antimicrob Agents Chemother 2012; 56:6304-9. [PMID: 23027185 DOI: 10.1128/aac.00813-12] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The echinocandins caspofungin, micafungin, and anidulafungin, inhibitors of cell wall β-1,3-glucan synthesis, were recently elevated to first-line agents for treating infections due to the azole-refractory yeast Candida glabrata. In Candida albicans, echinocandin resistance is strictly associated with mutations in Fks1, a large integral membrane protein and putative β-1,3-glucan synthase, while mutations in both Fks1 and its paralog Fks2 (but not Fks3) have been associated with resistance in C. glabrata. To further explore their function, regulation, and role in resistance, C. glabrata fks genes were disrupted and subjected to mutational analysis, and their differential regulation was explored. An fks1Δ fks2Δ double disruptant was not able to be generated; otherwise, all three single and remaining two double disruptants displayed normal growth and echinocandin susceptibility, indicating Fks1-Fks2 redundancy. Selection on echinocandin-containing medium for resistant mutants was dependent on strain background: only fks1Δ and fks1Δ fks3Δ strains consistently yielded mutants exhibiting high-level resistance, all with Fks2 hot spot 1 mutations. Thus, Fks1-Fks2 redundancy attenuates the rate of resistance; further analysis showed that it also attenuates the impact of resistance-conferring mutations. Growth of the fks1Δ and, especially, fks1Δ fks3Δ strains was specifically susceptible to the calcineurin inhibitor FK506. Relatedly, FK506 addition or calcineurin gene CMP2 disruption specifically reversed Fks2-mediated resistance of laboratory mutants and clinical isolates. RNA analysis suggests that transcriptional control is not the sole mechanism by which calcineurin modulates Fks2 activity.
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146
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Purisco SU, Martins MA, Szeszs MW, Castro e Silva DM, Pukinskas SR, Bonfietti LX, Baez AA, Melhem MS. Comparison of the broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing and the Clinical Laboratory Standards Institute BMD method for non-Candida albicans and non-C. tropicalis bloodstream isolates from eleven. FEMS Yeast Res 2012; 12:890-6. [DOI: 10.1111/j.1567-1364.2012.00838.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 07/30/2012] [Accepted: 07/31/2012] [Indexed: 11/28/2022] Open
Affiliation(s)
- Sonia U. Purisco
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Marilena A. Martins
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Maria W. Szeszs
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Dulcilena M. Castro e Silva
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Sandra R.B.S. Pukinskas
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Lucas X. Bonfietti
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Andres A. Baez
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
| | - Marcia S.C. Melhem
- Adolfo Lutz Institute; Coordination of Disease Control; Secretary of Health; Government of São Paulo State; São Paulo; Brazil
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Sasse C, Dunkel N, Schäfer T, Schneider S, Dierolf F, Ohlsen K, Morschhäuser J. The stepwise acquisition of fluconazole resistance mutations causes a gradual loss of fitness in Candida albicans. Mol Microbiol 2012; 86:539-56. [PMID: 22924823 DOI: 10.1111/j.1365-2958.2012.08210.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2012] [Indexed: 01/12/2023]
Abstract
The pathogenic yeast Candida albicans can develop resistance to the widely used antifungal agent fluconazole, which inhibits ergosterol biosynthesis. Resistance is often caused by gain-of-function mutations in the transcription factors Mrr1, Tac1 and Upc2, which result in constitutive overexpression of multidrug efflux pumps and ergosterol biosynthesis genes respectively. It is not known how the permanently changed gene expression program in resistant strains affects their fitness in the absence of drug selection pressure. We have systematically investigated the effects of activating mutations in Mrr1, Tac1 and Upc2, individually and in all possible combinations, on the degree of fluconazole resistance and on the fitness of C. albicans in an isogenic strain background. All combinations of different resistance mechanisms resulted in a stepwise increase in drug resistance, culminating in 500-fold increased fluconazole resistance in strains possessing mutations in the three transcription factors and an additional resistance mutation in the drug target enzyme Erg11. The acquisition of resistance mutations was associated with reduced fitness under non-selective conditions in vitro as well as in vivo during colonization of a mammalian host. Therefore, without compensatory mutations, the inability to appropriately regulate gene expression results in a loss of competitive fitness of drug-resistant C. albicans strains.
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Affiliation(s)
- Christoph Sasse
- Institut für Molekulare Infektionsbiologie, Universität Würzburg, Würzburg, Germany
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148
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Li QQ, Skinner J, Bennett JE. Evaluation of reference genes for real-time quantitative PCR studies in Candida glabrata following azole treatment. BMC Mol Biol 2012; 13:22. [PMID: 22747760 PMCID: PMC3482582 DOI: 10.1186/1471-2199-13-22] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 05/22/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The selection of stable and suitable reference genes for real-time quantitative PCR (RT-qPCR) is a crucial prerequisite for reliable gene expression analysis under different experimental conditions. The present study aimed to identify reference genes as internal controls for gene expression studies by RT-qPCR in azole-stimulated Candida glabrata. RESULTS The expression stability of 16 reference genes under fluconazole stress was evaluated using fold change and standard deviation computations with the hkgFinder tool. Our data revealed that the mRNA expression levels of three ribosomal RNAs (RDN5.8, RDN18, and RDN25) remained stable in response to fluconazole, while PGK1, UBC7, and UBC13 mRNAs showed only approximately 2.9-, 3.0-, and 2.5-fold induction by azole, respectively. By contrast, mRNA levels of the other 10 reference genes (ACT1, EF1α, GAPDH, PPIA, RPL2A, RPL10, RPL13A, SDHA, TUB1, and UBC4) were dramatically increased in C. glabrata following antifungal treatment, exhibiting changes ranging from 4.5- to 32.7-fold. We also assessed the expression stability of these reference genes using the 2(-ΔΔCT) method and three other software packages. The stability rankings of the reference genes by geNorm and the 2(-ΔΔCT) method were identical to those by hkgFinder, whereas the stability rankings by BestKeeper and NormFinder were notably different. We then validated the suitability of six candidate reference genes (ACT1, PGK1, RDN5.8, RDN18, UBC7, and UBC13) as internal controls for ten target genes in this system using the comparative CT method. Our validation experiments passed for all six reference genes analyzed except RDN18, where the amplification efficiency of RDN18 was different from that of the ten target genes. Finally, we demonstrated that the relative quantification of target gene expression varied according to the endogenous control used, highlighting the importance of the choice of internal controls in such experiments. CONCLUSIONS We recommend the use of RDN5.8, UBC13, and PGK1 alone or the combination of RDN5.8 plus UBC13 or PGK1 as reference genes for RT-qPCR analysis of gene expression in C. glabrata following azole treatment. In contrast, we show that ACT1 and other commonly used reference genes (GAPDH, PPIA, RPL13A, TUB1, etc.) were not validated as good internal controls in the current model.
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Affiliation(s)
- Qingdi Quentin Li
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Candida glabrata: Multidrug Resistance and Increased Virulence in a Major Opportunistic Fungal Pathogen. CURRENT FUNGAL INFECTION REPORTS 2012. [DOI: 10.1007/s12281-012-0091-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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150
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