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Nickels TJ, Gale AP, Harrington AA, Timp W, Cunningham KW. Tn-seq of the Candida glabrata reference strain CBS138 reveals epigenetic plasticity, structural variation, and intrinsic mechanisms of resistance to micafungin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592251. [PMID: 38746084 PMCID: PMC11092758 DOI: 10.1101/2024.05.02.592251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
C. glabrata is an opportunistic pathogen that can resist common antifungals and rapidly acquire multidrug resistance. A large amount of genetic variation exists between isolates, which complicates generalizations. Portable Tn-seq methods can efficiently provide genome-wide information on strain differences and genetic mechanisms. Using the Hermes transposon, the CBS138 reference strain and a commonly studied derivative termed 2001 were subjected to Tn-seq in control conditions and after exposure to varying doses of the clinical antifungal micafungin. The approach revealed large differences between these strains, including a 131 kb tandem duplication and a variety of fitness differences. Additionally, both strains exhibited up to 1000-fold increased transposon accessibility in subtelomeric regions relative to the BG2 strain, indicative of open subtelomeric chromatin in these isolates and large epigenetic variation within the species. Unexpectedly, the Pdr1 transcription factor conferred resistance to micafungin through targets other than CDR1 . Other micafungin resistance pathways were also revealed including mannosyltransferase activity and biosynthesis of the lipid precursor sphingosine, the drugging of which by SDZ 90-215 or myriocin enhanced the potency of micafungin in vitro . These findings provide insights into complexity of the C. glabrata species as well as strategies for improving antifungal efficacy. Summary Candida glabrata is an emerging pathogen with large genetic diversity and genome plasticity. The type strain CBS138 and a laboratory derivative were mutagenized with the Hermes transposon and profiled using Tn-seq. Numerous genes that regulate innate and acquired resistance to an important clinical antifungal were uncovered, including a pleiotropic drug resistance gene (PDR1) and a duplication of part of one chromosome. Compounds that target PDR1 and other genes may augment the potency of existing antifungals.
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Dunaiski CM, Kock MM, Chan WY, Ismail A, Peters RPH. Molecular epidemiology and antimicrobial resistance of vaginal Candida glabrata isolates in Namibia. Med Mycol 2024; 62:myae009. [PMID: 38308518 DOI: 10.1093/mmy/myae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/16/2023] [Accepted: 02/01/2024] [Indexed: 02/04/2024] Open
Abstract
Candida glabrata is the most common non-albicans Candida species that causes vulvovaginal candidiasis (VVC). Given the intrinsically low susceptibility of C. glabrata to azole drugs, investigations into C. glabrata prevalence, fungal susceptibility profile, and molecular epidemiology are necessary to optimise the treatment of VVC. This molecular epidemiological study was conducted to determine antifungal drug profile, single nucleotide polymorphisms (SNPs) associated with phenotypic antifungal resistance and epidemic diversity of C. glabrata isolates from women with VVC in Namibia. Candida glabrata isolates were identified using phenotypic and molecular methods. Antifungal susceptibility of strains was determined for fluconazole, itraconazole, amphotericin B, and anidulafungin. Whole genome sequencing was used to determine SNPs in antifungal resistance genes and sequence type (ST) allocation. Among C. glabrata isolates, all (20/20; 100%) exhibited phenotypic resistance to the azole class antifungal drug, (fluconazole), and phenotypic susceptibility to the polyene class (amphotericin B), and the echinocandins (anidulafungin). Non-synonymous SNPs were identified in antifungal resistance genes of all fluconazole-resistant C. glabrata isolates including ERG6 (15%), ERG7 (15%), CgCDR1 (25%), CgPDR1 (60%), SNQ2 (10%), FKS1 (5.0%), FKS2 (5.0%), CgFPS1 (5.0%), and MSH2 (15%). ST15 (n = 8/20, 40%) was predominant. This study provides important insight into phenotypic and genotypic antifungal resistance across C. glabrata isolates from women with VVC in Namibia. In this study, azole resistance is determined by an extensive range of SNPs, while the observed polyene and echinocandin resistance-associated SNPs despite phenotypic susceptibility require further investigation.
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Affiliation(s)
- Cara M Dunaiski
- Namibia University of Sciences and Technology, Department of Health and Applied Sciences, Windhoek 10005, Namibia
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
| | - Marleen M Kock
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
- National Health Laboratory Service, Tshwane, Academic Division, Pretoria 3191, South Africa
| | - Wai Yin Chan
- Sequencing Core Facility, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg 2131, South Africa
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0081, South Africa
- Right to care, Centurion 0157, South Africa
| | - Arshad Ismail
- Sequencing Core Facility, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg 2131, South Africa
- Department of Biochemistry and Microbiology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou 0950, South Africa
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa
| | - Remco P H Peters
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
- University of Cape Town, Division of Medical Microbiology, Cape Town 7701, South Africa
- Foundation for Professional Development, Research Unit, East London 5217, South Africa
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Billerbeck S, Prins RC, Marquardt M. A Modular Cloning Toolkit Including CRISPRi for the Engineering of the Human Fungal Pathogen and Biotechnology Host Candida glabrata. ACS Synth Biol 2023; 12:1358-1363. [PMID: 37043632 PMCID: PMC10127446 DOI: 10.1021/acssynbio.2c00560] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
The yeast Candida glabrata is an emerging, often drug-resistant opportunistic human pathogen that can cause severe systemic infections in immunocompromised individuals. At the same time, it is a valuable biotechnology host that naturally accumulates high levels of pyruvate─a valuable chemical precursor. Tools for the facile engineering of this yeast could greatly accelerate studies on its pathogenicity and its optimization for biotechnology. While a few tools for plasmid-based expression and genome engineering have been developed, there is no well-characterized cloning toolkit that would allow the modular assembly of pathways or genetic circuits. Here, by characterizing the Saccharomyces cerevisiae-based yeast molecular cloning toolkit (YTK) in C. glabrata and by adding missing components, we build a well-characterized CgTK (C. glabrata toolkit). We used the CgTK to build a CRISPR interference system for C. glabrata that can be used to generate selectable phenotypes via single-gRNA targeting such as is required for genome-wide library screens.
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Affiliation(s)
- Sonja Billerbeck
- Department for Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Rianne C Prins
- Department for Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Malte Marquardt
- Department for Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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Li Y, Zhang Q, Liu Z, Jiang H, Jia Q. Genome mining discovery of hydrogen production pathway of Klebsiella sp. WL1316 fermenting cotton stalk hydrolysate. Int Microbiol 2022; 25:503-513. [PMID: 35147786 DOI: 10.1007/s10123-022-00241-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/18/2022] [Accepted: 02/07/2022] [Indexed: 11/26/2022]
Abstract
Genome sequencing was used to identify key genes for the generation of hydrogen gas through cotton stalk hydrolysate fermentation by Klebsiella sp. WL1316. Genome annotation indicated that the genome size was 5.2 Mb with GC content 57.6%. Xylose was metabolized in the pentose phosphate pathway via the conversion of xylose to xylulose in Klebsiella sp. WL1316. This strain contained diverse formate-hydrogen lyases and hydrogenases with gene numbers higher than closely related species. A metabolic network involving glucose, xylose utilisation, and fermentative hydrogen production was reconstructed. Metabolic analysis of key node metabolites showed that glucose and xylose metabolism influenced biomass synthesis and biohydrogen production. Formic acid accumulated during fermentation at 24-48 h but decreased sharply after 48 h, illustrating the splitting of formic acid to hydrogen gas during early-to-mid fermentation. The Kreb's cycle was the main competitive metabolic branch of biohydrogen synthesis at 24 h of fermentation. Lactic and acetic acid fermentation and late ethanol accumulation competed the carbon skeleton of biohydrogen synthesis after 72 h of fermentation, indicating that these competitive pathways are regulated in middle-to-late fermentation (48-96 h). This study is the first to elucidate the metabolic mechanisms of mixed sugar utilisation and biohydrogen synthesis based on genomic information.
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Affiliation(s)
- Yanbin Li
- College of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, China
| | - Qin Zhang
- College of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, China.
| | - Zhanwen Liu
- College of Life Science, Tarim University, Alaer, 843300, Xinjiang, China
| | - Hui Jiang
- College of Life Science, Tarim University, Alaer, 843300, Xinjiang, China
| | - Qinghua Jia
- College of Life Science, Tarim University, Alaer, 843300, Xinjiang, China
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Metabolic pathway analysis of walnut endophytic bacterium Bacillus subtilis HB1310 related to lipid production from fermentation of cotton stalk hydrolysate based on genome sequencing. Biotechnol Lett 2021; 43:1883-1894. [PMID: 34228235 DOI: 10.1007/s10529-021-03160-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/28/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES In this study, genome sequencing and metabolic analysis were used to identify and verify the key metabolic pathways for glucose and xylose utilization and fatty acid synthesis in the walnut endophytic bacterium (WEB) Bacillus subtilis HB1310. RESULTS The genome sequence of WEB HB1310 was generated with a size of 4.1 Mb and GC content of 43.5%. Genome annotation indicated that the Embden-Meyerhof-Parnas, pentose phosphate, and fatty acid synthesis pathways were mainly involved in mixed sugar utilization and lipid production. In particular, diverse and abundant fatty acid synthesis genes were observed in a higher number than in other Bacillus strains. The tricarboxylic acid cycle competitively shared the carbon flux flowing before 48 h, and the acetic acid fermentation competed after 72 h. Moreover, fatty acid synthase activity was highly correlated with lipid titer with a correlation coefficient of 0.9626, and NADPH might be more utilized for the lipid synthesis within 48 h. CONCLUSIONS This study is the first attempt to explain the metabolic mechanism of mixed sugar utilization and lipid production based on genomic information, which provides a theoretical basis for the metabolic regulation of bacterial lipid production from lignocellulosic hydrolysates.
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Salazar SB, Wang C, Münsterkötter M, Okamoto M, Takahashi-Nakaguchi A, Chibana H, Lopes MM, Güldener U, Butler G, Mira NP. Comparative genomic and transcriptomic analyses unveil novel features of azole resistance and adaptation to the human host in Candida glabrata. FEMS Yeast Res 2019; 18:4566518. [PMID: 29087506 DOI: 10.1093/femsyr/fox079] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/24/2017] [Indexed: 11/14/2022] Open
Abstract
The frequent emergence of azole resistance among Candida glabrata strains contributes to increase the incidence of infections caused by this species. Whole-genome sequencing of a fluconazole and voriconazole-resistant clinical isolate (FFUL887) and subsequent comparison with the genome of the susceptible strain CBS138 revealed prominent differences in several genes documented to promote azole resistance in C. glabrata. Among these was the transcriptional regulator CgPdr1. The CgPdr1 FFUL887 allele included a K274Q modification not documented in other azole-resistant strains. Transcriptomic profiling evidenced the upregulation of 92 documented targets of CgPdr1 in the FFUL887 strain, supporting the idea that the K274Q substitution originates a CgPdr1 gain-of-function mutant. The expression of CgPDR1K274Q in the FFUL887 background sensitised the cells against high concentrations of organic acids at a low pH (4.5), but had no detectable effect in tolerance towards other environmental stressors. Comparison of the genome of FFUL887 and CBS138 also revealed prominent differences in the sequence of adhesin-encoding genes, while comparison of the transcriptome of the two strains showed a significant remodelling of the expression of genes involved in metabolism of carbohydrates, nitrogen and sulphur in the FFUL887 strain; these responses likely reflecting adaptive responses evolved by the clinical strain during colonisation of the host.
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Affiliation(s)
- Sara Barbosa Salazar
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico - Department of Bioengineering, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Can Wang
- School of Biomolecular and Biomedical Sciences, Conway Institute, University College of Dublin, Belfield, Dublin 4, Ireland
| | - Martin Münsterkötter
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany
| | - Michiyo Okamoto
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | | | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - Maria Manuel Lopes
- Faculdade de Farmácia da Universidade de Lisboa, Departamento de Microbiologia e Imunologia, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Ulrich Güldener
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany.,Chair of Genome-oriented Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Geraldine Butler
- School of Biomolecular and Biomedical Sciences, Conway Institute, University College of Dublin, Belfield, Dublin 4, Ireland
| | - Nuno Pereira Mira
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico - Department of Bioengineering, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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Lu Y, Ye C, Che J, Xu X, Shao D, Jiang C, Liu Y, Shi J. Genomic sequencing, genome-scale metabolic network reconstruction, and in silico flux analysis of the grape endophytic fungus Alternaria sp. MG1. Microb Cell Fact 2019; 18:13. [PMID: 30678677 PMCID: PMC6345013 DOI: 10.1186/s12934-019-1063-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/14/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Alternaria sp. MG1, an endophytic fungus isolated from grape, is a native producer of resveratrol, which has important application potential. However, the metabolic characteristics and physiological behavior of MG1 still remains mostly unraveled. In addition, the resveratrol production of the strain is low. Thus, the whole-genome sequencing is highly required for elucidating the resveratrol biosynthesis pathway. Furthermore, the metabolic network model of MG1 was constructed to provide a computational guided approach for improving the yield of resveratrol. RESULTS Firstly, a draft genomic sequence of MG1 was generated with a size of 34.7 Mbp and a GC content of 50.96%. Genome annotation indicated that MG1 possessed complete biosynthesis pathways for stilbenoids, flavonoids, and lignins. Eight secondary metabolites involved in these pathways were detected by GC-MS analysis, confirming the metabolic diversity of MG1. Furthermore, the first genome-scale metabolic network of Alternaria sp. MG1 (named iYL1539) was reconstructed, accounting for 1539 genes, 2231 metabolites, and 2255 reactions. The model was validated qualitatively and quantitatively by comparing the in silico simulation with experimental data, and the results showed a high consistency. In iYL1539, 56 genes were identified as growth essential in rich medium. According to constraint-based analysis, the importance of cofactors for the resveratrol biosynthesis was successfully demonstrated. Ethanol addition was predicted in silico to be an effective method to improve resveratrol production by strengthening acetyl-CoA synthesis and pentose phosphate pathway, and was verified experimentally with a 26.31% increase of resveratrol. Finally, 6 genes were identified as potential targets for resveratrol over-production by the recently developed methodology. The target-genes were validated using salicylic acid as elicitor, leading to an increase of resveratrol yield by 33.32% and the expression of gene 4CL and CHS by 1.8- and 1.6-fold, respectively. CONCLUSIONS This study details the diverse capability and key genes of Alternaria sp. MG1 to produce multiple secondary metabolites. The first model of the species Alternaria was constructed, providing an overall understanding of the physiological behavior and metabolic characteristics of MG1. The model is a highly useful tool for enhancing productivity by rational design of the metabolic pathway for resveratrol and other secondary metabolites.
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Affiliation(s)
- Yao Lu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, 710072, Shaanxi, China
| | - Chao Ye
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jinxin Che
- Department of Biological and Food Engineering, College of Chemical Engineering, Xiangtan University, Xiangtan, 411105, Hunan, China
| | - Xiaoguang Xu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, 710072, Shaanxi, China
| | - Dongyan Shao
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, 710072, Shaanxi, China
| | - Chunmei Jiang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, 710072, Shaanxi, China
| | - Yanlin Liu
- College of Enology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Junling Shi
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, 710072, Shaanxi, China.
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López-Fuentes E, Gutiérrez-Escobedo G, Timmermans B, Van Dijck P, De Las Peñas A, Castaño I. Candida glabrata's Genome Plasticity Confers a Unique Pattern of Expressed Cell Wall Proteins. J Fungi (Basel) 2018; 4:jof4020067. [PMID: 29874814 PMCID: PMC6023349 DOI: 10.3390/jof4020067] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 05/29/2018] [Accepted: 06/03/2018] [Indexed: 12/19/2022] Open
Abstract
Candida glabrata is the second most common cause of candidemia, and its ability to adhere to different host cell types, to microorganisms, and to medical devices are important virulence factors. Here, we consider three characteristics that confer extraordinary advantages to C. glabrata within the host. (1) C. glabrata has a large number of genes encoding for adhesins most of which are localized at subtelomeric regions. The number and sequence of these genes varies substantially depending on the strain, indicating that C. glabrata can tolerate high genomic plasticity; (2) The largest family of CWPs (cell wall proteins) is the EPA (epithelial adhesin) family of adhesins. Epa1 is the major adhesin and mediates adherence to epithelial, endothelial and immune cells. Several layers of regulation like subtelomeric silencing, cis-acting regulatory regions, activators, nutritional signaling, and stress conditions tightly regulate the expression of many adhesin-encoding genes in C. glabrata, while many others are not expressed. Importantly, there is a connection between acquired resistance to xenobiotics and increased adherence; (3) Other subfamilies of adhesins mediate adherence to Candida albicans, allowing C. glabrata to efficiently invade the oral epithelium and form robust biofilms. It is noteworthy that every C. glabrata strain analyzed presents a unique pattern of CWPs at the cell surface.
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Affiliation(s)
- Eunice López-Fuentes
- Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), División de Biología Molecular, Camino a la Presa San José 2055, San Luis Potosí, SLP 78216, Mexico.
| | - Guadalupe Gutiérrez-Escobedo
- Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), División de Biología Molecular, Camino a la Presa San José 2055, San Luis Potosí, SLP 78216, Mexico.
| | - Bea Timmermans
- KU Leuven, Laboratory of Molecular Cell Biology, Kasteelpark Arenberg 31 bus 2438, 3001 Leuven, Belgium.
- VIB-KU Leuven Center for Microbiology, 3001 Leuven, Belgium.
| | - Patrick Van Dijck
- KU Leuven, Laboratory of Molecular Cell Biology, Kasteelpark Arenberg 31 bus 2438, 3001 Leuven, Belgium.
- VIB-KU Leuven Center for Microbiology, 3001 Leuven, Belgium.
| | - Alejandro De Las Peñas
- Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), División de Biología Molecular, Camino a la Presa San José 2055, San Luis Potosí, SLP 78216, Mexico.
| | - Irene Castaño
- Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), División de Biología Molecular, Camino a la Presa San José 2055, San Luis Potosí, SLP 78216, Mexico.
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Carreté L, Ksiezopolska E, Pegueroles C, Gómez-Molero E, Saus E, Iraola-Guzmán S, Loska D, Bader O, Fairhead C, Gabaldón T. Patterns of Genomic Variation in the Opportunistic Pathogen Candida glabrata Suggest the Existence of Mating and a Secondary Association with Humans. Curr Biol 2017; 28:15-27.e7. [PMID: 29249661 PMCID: PMC5772174 DOI: 10.1016/j.cub.2017.11.027] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/13/2017] [Accepted: 11/09/2017] [Indexed: 12/30/2022]
Abstract
Candida glabrata is an opportunistic fungal pathogen that ranks as the second most common cause of systemic candidiasis. Despite its genus name, this yeast is more closely related to the model yeast Saccharomyces cerevisiae than to other Candida pathogens, and hence its ability to infect humans is thought to have emerged independently. Moreover, C. glabrata has all the necessary genes to undergo a sexual cycle but is considered an asexual organism due to the lack of direct evidence of sexual reproduction. To reconstruct the recent evolution of this pathogen and find footprints of sexual reproduction, we assessed genomic and phenotypic variation across 33 globally distributed C. glabrata isolates. We cataloged extensive copy-number variation, which particularly affects genes encoding cell-wall-associated proteins, including adhesins. The observed level of genetic variation in C. glabrata is significantly higher than that found in Candida albicans. This variation is structured into seven deeply divergent clades, which show recent geographical dispersion and large within-clade genomic and phenotypic differences. We show compelling evidence of recent admixture between differentiated lineages and of purifying selection on mating genes, which provides the first evidence for the existence of an active sexual cycle in this yeast. Altogether, our data point to a recent global spread of previously genetically isolated populations and suggest that humans are only a secondary niche for this yeast. Candida glabrata strains can be clustered into highly genetically divergent clades Genetic structure suggests a recent global spread of previously isolated populations The existence of sex in C. glabrata is supported by genomic footprints of selection Mating-type switching occurs in C. glabrata natural populations but is error prone
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Affiliation(s)
- Laia Carreté
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Ewa Ksiezopolska
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Cinta Pegueroles
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Emilia Gómez-Molero
- Institute for Medical Microbiology, University Medical Center Göttingen, Kreuzbergring 57, Göttingen 37075, Germany
| | - Ester Saus
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Susana Iraola-Guzmán
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Damian Loska
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Oliver Bader
- Institute for Medical Microbiology, University Medical Center Göttingen, Kreuzbergring 57, Göttingen 37075, Germany
| | - Cecile Fairhead
- GQE-Le Moulon, INRA-Université Paris-Sud-CNRS-AgroParisTech, 91400 Orsay, France
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain.
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Vale-Silva L, Beaudoing E, Tran VDT, Sanglard D. Comparative Genomics of Two Sequential Candida glabrata Clinical Isolates. G3 (BETHESDA, MD.) 2017; 7:2413-2426. [PMID: 28663342 PMCID: PMC5555451 DOI: 10.1534/g3.117.042887] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 06/26/2017] [Indexed: 01/14/2023]
Abstract
Candida glabrata is an important fungal pathogen which develops rapid antifungal resistance in treated patients. It is known that azole treatments lead to antifungal resistance in this fungal species and that multidrug efflux transporters are involved in this process. Specific mutations in the transcriptional regulator PDR1 result in upregulation of the transporters. In addition, we showed that the PDR1 mutations can contribute to enhance virulence in animal models. In this study, we were interested to compare genomes of two specific C. glabrata-related isolates, one of which was azole susceptible (DSY562) while the other was azole resistant (DSY565). DSY565 contained a PDR1 mutation (L280F) and was isolated after a time-lapse of 50 d of azole therapy. We expected that genome comparisons between both isolates could reveal additional mutations reflecting host adaptation or even additional resistance mechanisms. The PacBio technology used here yielded 14 major contigs (sizes 0.18-1.6 Mb) and mitochondrial genomes from both DSY562 and DSY565 isolates that were highly similar to each other. Comparisons of the clinical genomes with the published CBS138 genome indicated important genome rearrangements, but not between the clinical strains. Among the unique features, several retrotransposons were identified in the genomes of the investigated clinical isolates. DSY562 and DSY565 each contained a large set of adhesin-like genes (101 and 107, respectively), which exceed by far the number of reported adhesins (63) in the CBS138 genome. Comparison between DSY562 and DSY565 yielded 17 nonsynonymous SNPs (among which the was the expected PDR1 mutation) as well as small size indels in coding regions (11) but mainly in adhesin-like genes. The genomes contained a DNA mismatch repair allele of MSH2 known to be involved in the so-called hyper-mutator phenotype of this yeast species and the number of accumulated mutations between both clinical isolates is consistent with the presence of a MSH2 defect. In conclusion, this study is the first to compare genomes of C. glabrata sequential clinical isolates using the PacBio technology as an approach. The genomes of these isolates taken in the same patient at two different time points exhibited limited variations, even if submitted to the host pressure.
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Affiliation(s)
- Luis Vale-Silva
- Institute of Microbiology, University of Lausanne, CH-1011, Switzerland
- Lausanne University Hospital, CH-1011, Switzerland
| | - Emmanuel Beaudoing
- Center for Integrative Genomics, Lausanne Genomic Technologies Facility, CH-1015, Switzerland
| | - Van Du T Tran
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
| | - Dominique Sanglard
- Institute of Microbiology, University of Lausanne, CH-1011, Switzerland
- Lausanne University Hospital, CH-1011, Switzerland
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