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Ramírez-Zavala B, Hoffmann A, Krüger I, Schwanfelder S, Barker KS, Rogers PD, Morschhäuser J. Probing gene function in Candida albicans wild-type strains by Cas9-facilitated one-step integration of two dominant selection markers: a systematic analysis of recombination events at the target locus. mSphere 2024; 9:e0038824. [PMID: 38940507 PMCID: PMC11288041 DOI: 10.1128/msphere.00388-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 05/30/2024] [Indexed: 06/29/2024] Open
Abstract
The adaptation of gene deletion methods based on the CRISPR-Cas9 system has facilitated the genetic manipulation of the pathogenic yeast Candida albicans, because homozygous mutants of this diploid fungus can now be generated in a single step, allowing the rapid screening of candidate genes for their involvement in a phenotype of interest. However, the Cas9-mediated double-strand breaks at the target site may result in an undesired loss of heterozygosity (LOH) on the affected chromosome and cause phenotypic alterations that are not related to the function of the investigated gene. In our present study, we harnessed Cas9-facilitated gene deletion to probe a set of genes that are constitutively overexpressed in strains containing hyperactive forms of the transcription factor Mrr1 for a possible contribution to the fluconazole resistance of such strains. To this aim, we used gene deletion cassettes containing two different dominant selection markers, caSAT1 and HygB, which confer resistance to nourseothricin and hygromycin, respectively, for simultaneous genomic integration in a single step, hypothesizing that this would minimize undesired LOH events at the target locus. We found that selection for resistance to both nourseothricin and hygromycin strongly increased the proportion of homozygous deletion mutants among the transformants compared with selection on media containing only one of the antibiotics, but it did not avoid undesired LOH events. Our results demonstrate that LOH on the target chromosome is a significant problem when using Cas9 for the generation of C. albicans gene deletion mutants, which demands a thorough examination of recombination events at the target site. IMPORTANCE Candida albicans is one of the medically most important fungi and a model organism to study fungal pathogenicity. Investigating gene function in this diploid yeast has been facilitated by the adaptation of gene deletion methods based on the bacterial CRISPR-Cas9 system, because they enable the generation of homozygous mutants in a single step. We found that, in addition to increasing the efficiency of gene replacement by selection markers, the Cas9-mediated double-strand breaks also result in frequent loss of heterozygosity on the same chromosome, even when two different selection markers were independently integrated into the two alleles of the target gene. Since loss of heterozygosity for other genes can result in phenotypic alterations that are not caused by the absence of the target gene, these findings show that it is important to thoroughly analyze recombination events at the target locus when using Cas9 to generate gene deletion mutants in C. albicans.
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Affiliation(s)
| | - Anna Hoffmann
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Ines Krüger
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Sonja Schwanfelder
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Katherine S. Barker
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - P. David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Joachim Morschhäuser
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
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2
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Reitler P, Regan J, DeJarnette C, Srivastava A, Carnahan J, Tucker KM, Meibohm B, Peters BM, Palmer GE. The atypical antipsychotic aripiprazole alters the outcome of disseminated Candida albicans infections. Infect Immun 2024; 92:e0007224. [PMID: 38899880 PMCID: PMC11238555 DOI: 10.1128/iai.00072-24] [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: 02/14/2024] [Accepted: 04/29/2024] [Indexed: 06/21/2024] Open
Abstract
Invasive fungal infections impose an enormous clinical, social, and economic burden on humankind. One of the most common species responsible for invasive fungal infections is Candida albicans. More than 30% of patients with disseminated candidiasis fail therapy with existing antifungal drugs, including the widely used azole class. We previously identified a collection of 13 medications that antagonize the activity of the azoles on C. albicans. Although gain-of-function mutations responsible for antifungal resistance are often associated with reduced fitness and virulence, it is currently unknown how exposure to azole antagonistic drugs impacts C. albicans physiology, fitness, or virulence. In this study, we examined how exposure to seven azole antagonists affects C. albicans phenotype and capacity to cause disease. Most of the azole antagonists appear to have little impact on fungal growth, morphology, stress tolerance, or gene transcription. However, aripiprazole had a modest impact on C. albicans hyphal growth and increased cell wall chitin content. It also aggravated the disseminated C. albicans infections in mice. This effect was abrogated in immunosuppressed mice, indicating that it is at least in part dependent upon host immune responses. Collectively, these data provide proof of principle that unanticipated drug-fungus interactions have the potential to influence the incidence and outcomes of invasive fungal disease.
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Affiliation(s)
- Parker Reitler
- Integrated Program in Biomedical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jessica Regan
- Pharmaceutical Sciences Program, College of Graduate Health Sciences, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Christian DeJarnette
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Ashish Srivastava
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jen Carnahan
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Katie M Tucker
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Bernd Meibohm
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Brian M Peters
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Glen E Palmer
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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3
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Bergin S, Doorley LA, Rybak JM, Wolfe KH, Butler G, Cuomo CA, Rogers PD. Analysis of clinical Candida parapsilosis isolates reveals copy number variation in key fluconazole resistance genes. Antimicrob Agents Chemother 2024:e0161923. [PMID: 38712935 DOI: 10.1128/aac.01619-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 04/08/2024] [Indexed: 05/08/2024] Open
Abstract
We used whole-genome sequencing to analyze a collection of 35 fluconazole-resistant and 7 susceptible Candida parapsilosis isolates together with coverage analysis and GWAS techniques to identify new mechanisms of fluconazole resistance. Phylogenetic analysis shows that although the collection is diverse, two persistent clinical lineages were identified. We identified copy number variation (CNV) of two genes, ERG11 and CDR1B, in resistant isolates. Two strains have a CNV at the ERG11 locus; the entire ORF is amplified in one, and only the promoter region is amplified in the other. We show that the annotated telomeric gene CDR1B is actually an artifactual in silico fusion of two highly similar neighboring CDR genes due to an assembly error in the C. parapsilosis CDC317 reference genome. We report highly variable copy numbers of the CDR1B region across the collection. Several strains have increased the expansion of the two genes into a tandem array of new chimeric genes. Other strains have experienced a deletion between the two genes creating a single gene with a reciprocal chimerism. We find translocations, duplications, and gene conversion across the CDR gene family in the C. parapsilosis species complex, showing that it is a highly dynamic family.
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Affiliation(s)
- Sean Bergin
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Laura A Doorley
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jeffrey M Rybak
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Kenneth H Wolfe
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Molecular Microbiology and Immunology Department, Brown University, Providence, Rhode Island, USA
| | - P David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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Wang J, Shen J, Chen D, Liao B, Chen X, Zong Y, Wei Y, Shi Y, Liu Y, Gou L, Zhou X, Cheng L, Ren B. Secretory IgA reduced the ergosterol contents of Candida albicans to repress its hyphal growth and virulence. Appl Microbiol Biotechnol 2024; 108:244. [PMID: 38421461 PMCID: PMC10904422 DOI: 10.1007/s00253-024-13063-z] [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: 10/28/2023] [Revised: 01/31/2024] [Accepted: 02/08/2024] [Indexed: 03/02/2024]
Abstract
Candida albicans, one of the most prevalent conditional pathogenic fungi, can cause local superficial infections and lethal systemic infections, especially in the immunocompromised population. Secretory immunoglobulin A (sIgA) is an important immune protein regulating the pathogenicity of C. albicans. However, the actions and mechanisms that sIgA exerts directly against C. albicans are still unclear. Here, we investigated that sIgA directs against C. albicans hyphal growth and virulence to oral epithelial cells. Our results indicated that sIgA significantly inhibited C. albicans hyphal growth, adhesion, and damage to oral epithelial cells compared with IgG. According to the transcriptome and RT-PCR analysis, sIgA significantly affected the ergosterol biosynthesis pathway. Furthermore, sIgA significantly reduced the ergosterol levels, while the addition of exogenous ergosterol restored C. albicans hyphal growth and adhesion to oral epithelial cells, indicating that sIgA suppressed the growth of hyphae and the pathogenicity of C. albicans by reducing its ergosterol levels. By employing the key genes mutants (erg11Δ/Δ, erg3Δ/Δ, and erg3Δ/Δ erg11Δ/Δ) from the ergosterol pathway, sIgA lost the hyphal inhibition on these mutants, while sIgA also reduced the inhibitory effects of erg11Δ/Δ and erg3Δ/Δ and lost the inhibition of erg3Δ/Δ erg11Δ/Δ on the adhesion to oral epithelial cells, further proving the hyphal repression of sIgA through the ergosterol pathway. We demonstrated for the first time that sIgA inhibited C. albicans hyphal development and virulence by affecting ergosterol biosynthesis and suggest that ergosterol is a crucial regulator of C. albicans-host cell interactions. KEY POINTS: • sIgA repressed C. albicans hyphal growth • sIgA inhibited C. albicans virulence to host cells • sIgA affected C. albicans hyphae and virulence by reducing its ergosterol levels.
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Affiliation(s)
- Jiannan Wang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jiawei Shen
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Ding Chen
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Binyou Liao
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xi Chen
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yawen Zong
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yu Wei
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yangyang Shi
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yaqi Liu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lichen Gou
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lei Cheng
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
- Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
| | - Biao Ren
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
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Wu Z, Bi Y, Zhang J, Gao T, Li X, Hao J, Li G, Liu P, Liu X. Multidrug resistance of Botrytis cinerea associated with its adaptation to plant secondary metabolites. mBio 2024; 15:e0223723. [PMID: 38259067 PMCID: PMC10865845 DOI: 10.1128/mbio.02237-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024] Open
Abstract
Fungicides are an effective way to control gray mold of grapes, but the pathogen Botrytis cinerea can develop resistance, overcoming the effectiveness of a fungicide that is repeatedly applied. More importantly, the emergence of multidrug resistance (MDR) in the field, where multiple fungicides with different modes of action simultaneously lose their efficacies, is a significant concern. MDR is associated with ATP-binding cassette (ABC) transporters of the pathogen, and certain plant secondary metabolites (PSMs) stimulate the upregulation of ABC transporters, we hypothesized that the pathogen's preadaptation to PSMs might contribute to MDR development. To test this in B. cinerea, ten PSMs, namely, resveratrol, reserpine, chalcone, flavanone, eugenol, farnesol, anethene, camptothecin, salicylic acid, and psoralen, were selected based on their association with ABC transporters involved in fungicide resistance. B. cinerea strain B05.10 was continuously transferred for 15 generations on potato dextrose agar amended with a PSM (PDAP), and sensitivities to PSMs and fungicides were examined on the 5th, 10th, and 15th generations. RNA was extracted from B. cinerea from the selected generations. After 15 generations of culture transfers, an up-regulation was observed in the expression of ABC transporter-encoding genes BcatrB, BcatrD, and BcatrK using quantitative polymerase chain reaction (qPCR). This upregulation was found to contribute to MDR of B. cinerea against two or more fungicides, among azoxystrobin, boscalid, fludioxonil, difenoconazole, prochloraz, and pyrimethanil. This finding was confirmed through genetic transformation. The decreased sensitivity of B. cinerea to fungicides was confirmed as a subsequent MDR phenotype after exposure to camptothecin, flavanone, and resveratrol. Besides, transcriptome analysis also revealed the upregulation of transcription factors related to ABC expression following resveratrol exposure. This suggests that PSMs contributed to inducing preadaptation of B. cinerea, leading to subsequent MDR.IMPORTANCEThe emergence of MDR in plant pathogens is a threat to plant disease management and leads to the use of excessive fungicides. Botrytis cinerea is of particular concern because its MDR has widely emerged in the field. Understanding its genesis is the first step for controlling MDR. In this study, the contribution of PSMs to MDR has been examined. Effective management of this pathogen in agroecosystems relies on a better understanding of how it copes with phytochemicals or fungicides.
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Affiliation(s)
- Zhaochen Wu
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Yue Bi
- Department of Plant Pathology, China Agricultural University, Beijing, China
- Department of Plant Pathology, Tianjin Agricultural University, Tianjin, China
| | - Junting Zhang
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Tuqiang Gao
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Xueming Li
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Jianjun Hao
- School of Food and Agriculture, University of Maine, Orono, Maine, USA
| | - Guihua Li
- College of Plant Sciences, Jilin University, Changchun, China
| | - Pengfei Liu
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Xili Liu
- Department of Plant Pathology, China Agricultural University, Beijing, China
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Reitler P, Regan J, DeJarnette C, Srivastava A, Carnahan J, Tucker KM, Meibohm B, Peters BM, Palmer GE. The atypical antipsychotic aripiprazole alters the outcome of disseminated Candida albicans infections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580133. [PMID: 38405954 PMCID: PMC10888916 DOI: 10.1101/2024.02.13.580133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Invasive fungal infections (IFIs) impose an enormous clinical, social, and economic burden on humankind. For many IFIs, ≥ 30% of patients fail therapy with existing antifungal drugs, including the widely used azole class. We previously identified a collection of 13 approved medications that antagonize azole activity. While gain-of-function mutants resulting in antifungal resistance are often associated with reduced fitness and virulence, it is currently unknown how exposure to azole antagonistic drugs impact C. albicans physiology, fitness, or virulence. In this study, we examined how exposure to azole antagonists affected C. albicans phenotype and capacity to cause disease. We discovered that most of the azole antagonists had little impact on fungal growth, morphology, stress tolerance, or gene transcription. However, aripiprazole had a modest impact on C. albicans hyphal growth and increased cell wall chitin content. It also worsened the outcome of disseminated infections in mice at human equivalent concentrations. This effect was abrogated in immunosuppressed mice, indicating an additional impact of aripiprazole on host immunity. Collectively, these data provide proof-of-principle that unanticipated drug-fungus interactions have the potential to influence the incidence and outcomes of invasive fungal disease.
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Affiliation(s)
- Parker Reitler
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jessica Regan
- Pharmaceutical Sciences Program, College of Graduate Health Sciences, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Christian DeJarnette
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Ashish Srivastava
- Department of Pharmaceutical Sciences College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Jen Carnahan
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Katie M. Tucker
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Bernd Meibohm
- Department of Pharmaceutical Sciences College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Brian M Peters
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Glen E. Palmer
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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7
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Bergin S, Doorley LA, Rybak JM, Wolfe KH, Butler G, Cuomo CA, Rogers PD. Analysis of clinical Candida parapsilosis isolates reveals copy number variation in key fluconazole resistance genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.571446. [PMID: 38168157 PMCID: PMC10760152 DOI: 10.1101/2023.12.13.571446] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
We used whole-genome sequencing to analyse a collection of 35 fluconazole resistant and 7 susceptible Candida parapsilosis isolates together with coverage analysis and GWAS techniques to identify new mechanisms of fluconazole resistance. Phylogenetic analysis shows that although the collection is diverse, two probable outbreak groups were identified. We identified copy number variation of two genes, ERG11 and CDR1B, in resistant isolates. Two strains have a CNV at the ERG11 locus; the entire ORF is amplified in one, and only the promoter region is amplified in the other. We show the annotated telomeric gene CDR1B is actually an artefactual in silico fusion of two highly similar neighbouring CDR genes due to an assembly error in the C. parapsilosis CDC317 reference genome. We report highly variable copy numbers of the CDR1B region across the collection. Several strains have increased expansion of the two genes into a tandem array of new chimeric genes. Other strains have experienced a deletion between the two genes creating a single gene with a reciprocal chimerism. We find translocations, duplications, and gene conversion across the CDR gene family in the C. parapsilosis species complex, showing that it is a highly dynamic family.
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Affiliation(s)
- Sean Bergin
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Laura A Doorley
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jeffrey M Rybak
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Kenneth H Wolfe
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Molecular Microbiology and Immunology Department, Brown University, Providence, RI, USA
| | - P David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
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8
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Shrivastava M, Kouyoumdjian GS, Kirbizakis E, Ruiz D, Henry M, Vincent AT, Sellam A, Whiteway M. The Adr1 transcription factor directs regulation of the ergosterol pathway and azole resistance in Candida albicans. mBio 2023; 14:e0180723. [PMID: 37791798 PMCID: PMC10653825 DOI: 10.1128/mbio.01807-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 10/05/2023] Open
Abstract
IMPORTANCE Research often relies on well-studied orthologs within related species, with researchers using a well-studied gene or protein to allow prediction of the function of the ortholog. In the opportunistic pathogen Candida albicans, orthologs are usually compared with Saccharomyces cerevisiae, and this approach has been very fruitful. Many transcription factors (TFs) do similar jobs in the two species, but many do not, and typically changes in function are driven not by modifications in the structures of the TFs themselves but in the connections between the transcription factors and their regulated genes. This strategy of changing TF function has been termed transcription factor rewiring. In this study, we specifically looked for rewired transcription factors, or Candida-specific TFs, that might play a role in drug resistance. We investigated 30 transcription factors that were potentially rewired or were specific to the Candida clade. We found that the Adr1 transcription factor conferred resistance to drugs like fluconazole, amphotericin B, and terbinafine when activated. Adr1 is known for fatty acid and glycerol utilization in Saccharomyces, but our study reveals that it has been rewired and is connected to ergosterol biosynthesis in Candida albicans.
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Affiliation(s)
- Manjari Shrivastava
- Department of Biology, Concordia University, Montréal, Quebec, Canada
- Center for research, Montreal Heart Institute, Montréal, Quebec, Canada
- Department of Microbiology, Infectiology and Immunology, Faculty of Medicine, Université de Montréal, Montréal, Quebec, Canada
| | | | | | - Daniel Ruiz
- Department of Biology, Concordia University, Montréal, Quebec, Canada
| | - Manon Henry
- Center for research, Montreal Heart Institute, Montréal, Quebec, Canada
- Department of Microbiology, Infectiology and Immunology, Faculty of Medicine, Université de Montréal, Montréal, Quebec, Canada
| | - Antony T. Vincent
- Department of Animal Sciences, Université Laval, Quebec City, Canada
| | - Adnane Sellam
- Center for research, Montreal Heart Institute, Montréal, Quebec, Canada
- Department of Microbiology, Infectiology and Immunology, Faculty of Medicine, Université de Montréal, Montréal, Quebec, Canada
| | - Malcolm Whiteway
- Department of Biology, Concordia University, Montréal, Quebec, Canada
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9
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Gervais NC, La Bella AA, Wensing LF, Sharma J, Acquaviva V, Best M, Cadena López RO, Fogal M, Uthayakumar D, Chavez A, Santiago-Tirado F, Flores-Mireles AL, Shapiro RS. Development and applications of a CRISPR activation system for facile genetic overexpression in Candida albicans. G3 (BETHESDA, MD.) 2023; 13:jkac301. [PMID: 36450451 PMCID: PMC9911074 DOI: 10.1093/g3journal/jkac301] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/02/2021] [Accepted: 11/04/2022] [Indexed: 12/02/2022]
Abstract
For the fungal pathogen Candida albicans, genetic overexpression readily occurs via a diversity of genomic alterations, such as aneuploidy and gain-of-function mutations, with important consequences for host adaptation, virulence, and evolution of antifungal drug resistance. Given the important role of overexpression on C. albicans biology, it is critical to develop and harness tools that enable the analysis of genes expressed at high levels in the fungal cell. Here, we describe the development, optimization, and application of a novel, single-plasmid-based CRISPR activation (CRISPRa) platform for targeted genetic overexpression in C. albicans, which employs a guide RNA to target an activator complex to the promoter region of a gene of interest, thus driving transcriptional expression of that gene. Using this system, we demonstrate the ability of CRISPRa to drive high levels of gene expression in C. albicans, and we assess optimal guide RNA targeting for robust and constitutive overexpression. We further demonstrate the specificity of the system via RNA sequencing. We highlight the application of CRISPR activation to overexpress genes involved in pathogenesis and drug susceptibility, and contribute toward the identification of novel phenotypes. Consequently, this tool will facilitate a broad range of applications for the study of C. albicans genetic overexpression.
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Affiliation(s)
- Nicholas C Gervais
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Alyssa A La Bella
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Lauren F Wensing
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Jehoshua Sharma
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Victoria Acquaviva
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Madison Best
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | | | - Meea Fogal
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Deeva Uthayakumar
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
- Present address: Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Alejandro Chavez
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | | | - Ana L Flores-Mireles
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
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10
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Wang WY, Cai HQ, Qu SY, Lin WH, Liang CC, Liu H, Xie ZX, Yuan YJ. Genomic Variation-Mediating Fluconazole Resistance in Yeast. Biomolecules 2022; 12:biom12060845. [PMID: 35740970 PMCID: PMC9221393 DOI: 10.3390/biom12060845] [Citation(s) in RCA: 4] [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: 04/28/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/16/2022] Open
Abstract
Fungal infections pose a serious and growing threat to public health. These infections can be treated with antifungal drugs by killing hazardous fungi in the body. However, the resistance can develop over time when fungi are exposed to antifungal drugs by generating genomic variations, including mutation, aneuploidy, and loss of heterozygosity. The variations could reduce the binding affinity of a drug to its target or block the pathway through which drugs exert their activity. Here, we review genomic variation-mediating fluconazole resistance in the yeast Candida, with the hope of highlighting the functional consequences of genomic variations for the antifungal resistance.
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11
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The Role of Glycoside Hydrolases in S. gordonii and C. albicans Interactions. Appl Environ Microbiol 2022; 88:e0011622. [PMID: 35506689 DOI: 10.1128/aem.00116-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Candida albicans can coaggregate with Streptococcus gordonii and cocolonize in the oral cavity. Saliva provides a vital microenvironment for close interactions of oral microorganisms. However, the level of fermentable carbohydrates in saliva is not sufficient to support the growth of multiple species. Glycoside hydrolases (GHs) that hydrolyze glycoproteins are critical for S. gordonii growth in low-fermentable-carbohydrate environments such as saliva. However, whether GHs are involved in the cross-kingdom interactions between C. albicans and S. gordonii under such conditions remains unknown. In this study, C. albicans and S. gordonii were cocultured in heart infusion broth with a low level of fermentable carbohydrate. Planktonic growth, biofilm formation, cell aggregation, and GH activities of monocultures and cocultures were examined. The results revealed that the planktonic growth of cocultured S. gordonii in a low-carbohydrate environment was elevated, while that of cocultured C. albicans was reduced. The biomass of S. gordonii in dual-species biofilms was higher than that of monocultures, while that of cocultured C. albicans was decreased. GH activity was observed in S. gordonii, and elevated activity of GHs was detected in S. gordonii-C. albicans cocultures, with elevated expression of GH-related genes of S. gordonii. By screening a mutant library of C. albicans, we identified a tec1Δ/Δ mutant strain that showed reduced ability to promote the growth and GH activities of S. gordonii compared with the wild-type strain. Altogether, the findings of this study demonstrate the involvement of GHs in the cross-kingdom metabolic interactions between C. albicans and S. gordonii in an environment with low level of fermentable carbohydrates. IMPORTANCE Cross-kingdom interactions between Candida albicans and oral streptococci such as Streptococcus gordonii have been reported. However, their interactions in a low-fermentable-carbohydrate environment like saliva is not clear. The current study revealed glycoside hydrolase-related cross-kingdom communications between S. gordonii and C. albicans under the low-fermentable-carbohydrate condition. We demonstrate that C. albicans can promote the growth and metabolic activities of S. gordonii by elevating the activities of cell-wall-anchored glycoside hydrolases of S. gordonii. C. albicans gene TEC1 is critical for this cross-kingdom metabolic communication.
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12
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Ribeiro GF, Denes E, Heaney H, Childers DS. What 'Omics Can Tell Us About Antifungal Adaptation. FEMS Yeast Res 2021; 21:6484793. [PMID: 34958354 PMCID: PMC8755904 DOI: 10.1093/femsyr/foab070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/22/2021] [Indexed: 12/01/2022] Open
Abstract
Invasive candidiasis, the most frequent healthcare-associated invasive fungal infection, is commonly caused by Candida albicans. However, in recent years other antifungal-resistant Candida species—namely Candida glabrata and Candidaauris—have emerged as a serious matter of concern. Much of our understanding of the mechanisms regulating antifungal resistance and tolerance relies on studies utilizing C. albicans, C. glabrataand the model yeast Saccharomyces cerevisiae. ‘Omics studies have been used to describe alterations in metabolic, genomic and transcriptomic expression profiles upon antifungal treatment of fungal cells. The physiological changes identified by these approaches could significantly affect fungal fitness in the host and survival during antifungal challenge, as well as provide further understanding of clinical resistance. Thus, this review aims to comparatively address ‘omics data for C. albicans, C. glabrata andS. cerevisiae published from 2000 to 2021 to identify what these technologies can tell us regarding cellular responses to antifungal therapy. We will also highlight possible effects on pathogen survival and identify future avenues for antifungal research.
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Affiliation(s)
- Gabriela Fior Ribeiro
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Eszter Denes
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Helen Heaney
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Delma S Childers
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
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13
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Hassanpour P, Hamishehkar H, Bahari Baroughi B, Baradaran B, Sandoghchian Shotorbani S, Mohammadi M, Shomali N, Aghebati-Maleki L, Nami S. Antifungal Effects of Voriconazole-Loaded Nano-Liposome on Fluconazole -Resistant Clinical Isolates of Candida albicans, Biological Activity and ERG11, CDR1, and CDR2 Gene Expression. Assay Drug Dev Technol 2021; 19:453-462. [PMID: 34435891 DOI: 10.1089/adt.2020.1057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study aimed to assess the effect of voriconazole (VCZ)-loaded nano-liposomes on biological activity and expression of ERG11, CDR1, and CDR2 genes in fluconazole (FCZ)-resistant Candida albicans. In this study, 5 resistant isolates of C. albicans and 3 susceptible clinical isolates to FCZ were scrutinized from 60 patients suspected of candidiasis. The liposomal formulation of VCZ was produced. After that, the minimum biofilm inhibitory concentration (MBIC) testing was performed and the percentage of growth inhibition was determined. Finally, ERG11, CDR1, and CDR2 mRNA levels were amplified by the quantitative reverse transcription PCR (qRT-PCR) instrument. The obtained results unveiled that VCZ-loaded nano-liposome reduction of minimum inhibitory concentration in C. albicans isolates was remarkable. The results of the MBIC in the most optimum inhibitory concentration of VCZ-loaded nano-liposome were determined to be 4.54 and 4.88 μg/mL for susceptible isolate and resistant isolate, respectively. The ERG11 gene expression in FCZ-resistant C. albicans strains in VCZ-treated, liposomal formulation of VCZ-treated, and nontreated specimens stood at 91%, 63%, and 100%, respectively. Expression levels of CDR1 genes in FCZ-resistant C. albicans were shown to be 91%, 88%, and 100%, respectively. Concerning CDR2 genes, this rate varied to 91%, 78%, and 100% in FCZ resistant, respectively. What our study unveiled was that the use of liposomal VCZ formulation could further reduce the expression of azole-resistant genes compared to VCZ itself. In addition, thanks to more efficacious penetration of the liposomal form, the rate of growth inhibition was considerably higher.
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Affiliation(s)
- Parviz Hassanpour
- Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamed Hamishehkar
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Maryam Mohammadi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Biotechnology Research Center and Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Navid Shomali
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Leili Aghebati-Maleki
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Immunology, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sanam Nami
- Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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14
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Sitterlé E, Coste AT, Obadia T, Maufrais C, Chauvel M, Sertour N, Sanglard D, Puel A, D'Enfert C, Bougnoux ME. Large-scale genome mining allows identification of neutral polymorphisms and novel resistance mutations in genes involved in Candida albicans resistance to azoles and echinocandins. J Antimicrob Chemother 2021; 75:835-848. [PMID: 31923309 DOI: 10.1093/jac/dkz537] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/22/2019] [Accepted: 12/01/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The genome of Candida albicans displays significant polymorphism. Point mutations in genes involved in resistance to antifungals may either confer phenotypic resistance or be devoid of phenotypic consequences. OBJECTIVES To catalogue polymorphisms in azole and echinocandin resistance genes occurring in susceptible strains in order to rapidly pinpoint relevant mutations in resistant strains. METHODS Genome sequences from 151 unrelated C. albicans strains susceptible to fluconazole and caspofungin were used to create a catalogue of non-synonymous polymorphisms in genes involved in resistance to azoles (ERG11, TAC1, MRR1 and UPC2) or echinocandins (FKS1). The potential of this catalogue to reveal putative resistance mutations was tested in 10 azole-resistant isolates, including 1 intermediate to caspofungin. Selected mutations were analysed by mutagenesis experiments or mutational prediction effect. RESULTS In the susceptible strains, we identified 126 amino acid substitutions constituting the catalogue of phenotypically neutral polymorphisms. By excluding these neutral substitutions, we identified 22 additional substitutions in the 10 resistant strains. Among these substitutions, 10 had already been associated with resistance. The remaining 12 were in Tac1p (n = 6), Upc2p (n = 2) and Erg11p (n = 4). Four out of the six homozygous substitutions in Tac1p (H263Y, A790V, H839Y and P971S) conferred increases in azole MICs, while no effects were observed for those in Upc2p. Additionally, two homozygous substitutions (Y64H and P236S) had a predicted conformation effect on Erg11p. CONCLUSIONS By establishing a catalogue of neutral polymorphisms occurring in genes involved in resistance to antifungal drugs, we provide a useful resource for rapid identification of mutations possibly responsible for phenotypic resistance in C. albicans.
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Affiliation(s)
- Emilie Sitterlé
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Unité de Parasitologie-Mycologie, Service de Microbiologie clinique, Hôpital Necker-Enfants-Malades, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France
| | - Alix T Coste
- Institut de Microbiologie, Université de Lausanne et Centre Hospitalo-Universitaire, Lausanne, Switzerland
| | - Thomas Obadia
- Hub de Bioinformatique et Biostatistique, Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France.,Unité Malaria: parasites et hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Corinne Maufrais
- Hub de Bioinformatique et Biostatistique, Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Murielle Chauvel
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France
| | - Natacha Sertour
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France
| | - Dominique Sanglard
- Institut de Microbiologie, Université de Lausanne et Centre Hospitalo-Universitaire, Lausanne, Switzerland
| | - Anne Puel
- Laboratoire de génétique humaine des maladies infectieuses, Necker, INSERM U1163, Paris, France.,Université Paris Descartes, Institut Imagine, Paris, France
| | - Christophe D'Enfert
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France.,Unité de Parasitologie-Mycologie, Service de Microbiologie clinique, Hôpital Necker-Enfants-Malades, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France.,Université de Paris, Paris, France
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15
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Nishimoto AT, Sharma C, Rogers PD. Molecular and genetic basis of azole antifungal resistance in the opportunistic pathogenic fungus Candida albicans. J Antimicrob Chemother 2021; 75:257-270. [PMID: 31603213 DOI: 10.1093/jac/dkz400] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Candida albicans is an opportunistic yeast and the major human fungal pathogen in the USA, as well as in many other regions of the world. Infections with C. albicans can range from superficial mucosal and dermatological infections to life-threatening infections of the bloodstream and vital organs. The azole antifungals remain an important mainstay treatment of candidiasis and therefore the investigation and understanding of the evolution, frequency and mechanisms of azole resistance are vital to improving treatment strategies against this organism. Here the organism C. albicans and the genetic changes and molecular bases underlying the currently known resistance mechanisms to the azole antifungal class are reviewed, including up-regulated expression of efflux pumps, changes in the expression and amino acid composition of the azole target Erg11 and alterations to the organism's typical sterol biosynthesis pathways. Additionally, we update what is known about activating mutations in the zinc cluster transcription factor (ZCF) genes regulating many of these resistance mechanisms and review azole import as a potential contributor to azole resistance. Lastly, investigations of azole tolerance in C. albicans and its implicated clinical significance are reviewed.
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Affiliation(s)
- Andrew T Nishimoto
- Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Cheshta Sharma
- Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - P David Rogers
- Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
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16
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Maras B, Maggiore A, Mignogna G, D’Erme M, Angiolella L. Hyperexpression of CDRs and HWP1 genes negatively impacts on Candida albicans virulence. PLoS One 2021; 16:e0252555. [PMID: 34061886 PMCID: PMC8168907 DOI: 10.1371/journal.pone.0252555] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/18/2021] [Indexed: 02/03/2023] Open
Abstract
C. albicans is a commensal organism present in the human microbiome of more than 60% of the healthy population. Transition from commensalism to invasive candidiasis may occur after a local or a general failure of host’s immune system. This transition to a more virulent phenotype may reside either on the capacity to form hyphae or on an acquired resistance to antifungal drugs. Indeed, overexpression of genes coding drug efflux pumps or adhesins, cell wall proteins facilitating the contact between the fungus and the host, usually marks the virulence profile of invasive Candida spp. In this paper, we compare virulence of two clinical isolates of C. albicans with that of laboratory-induced resistant strains by challenging G. mellonella larvae with these pathogens along with monitoring transcriptional profiles of drug efflux pumps genes CDR1, CDR2, MDR1 and the adhesin genes ALS1 and HWP1. Although both clinical isolates were found resistant to both fluconazole and micafungin they were found less virulent than laboratory-induced resistant strains. An unexpected behavior emerged for the former clinical isolate in which three genes, CDR1, CDR2 and HWP1, usually correlated with virulence, although hyperexpressed, conferred a less aggressive phenotype. On the contrary, in the other isolate, we observed a decreased expression of CDR1, CDR2 and HWP1as well as of MDR1 and ALS1 that may be consistent with the less aggressive performance observed in this strain. These altered gene expressions might directly influence Candida virulence or they might be an epiphenomenon of a vaster rearrangement occurred in these strains during the challenge with the host’s environment. An in-deepth comprehension of this scenario could be crucial for developing interventions able to counteract C. albicans invasiveness and lethality.
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Affiliation(s)
- Bruno Maras
- Dipartimento di Scienze Biochimiche ‘‘A. Rossi Fanelli”, Sapienza Universita`di Roma, Rome, Italy
| | - Anna Maggiore
- Dipartimento di Scienze Biochimiche ‘‘A. Rossi Fanelli”, Sapienza Universita`di Roma, Rome, Italy
| | - Giuseppina Mignogna
- Dipartimento di Scienze Biochimiche ‘‘A. Rossi Fanelli”, Sapienza Universita`di Roma, Rome, Italy
| | - Maria D’Erme
- Dipartimento di Scienze Biochimiche ‘‘A. Rossi Fanelli”, Sapienza Universita`di Roma, Rome, Italy
| | - Letizia Angiolella
- Dipartimento di Sanita`Pubblica e Malattie Infettive, Sapienza Universita`di Roma, Rome, Italy
- * E-mail:
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17
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Bezerra AR, Oliveira C, Correia I, Guimarães AR, Sousa G, Carvalho MJ, Moura G, Santos MAS. The role of non-standard translation in Candida albicans pathogenesis. FEMS Yeast Res 2021; 21:6280978. [PMID: 34021562 PMCID: PMC8178436 DOI: 10.1093/femsyr/foab032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/20/2021] [Indexed: 12/22/2022] Open
Abstract
Candida albicans typically resides in the human gastrointestinal tract and mucosal membranes as a commensal organism. To adapt and cope with the host immune system, it has evolved a variety of mechanisms of adaptation such as stress-induced mutagenesis and epigenetic regulation. Niche-specific patterns of gene expression also allow the fungus to fine-tune its response to specific microenvironments in the host and switch from harmless commensal to invasive pathogen. Proteome plasticity produced by CUG ambiguity, on the other hand is emerging as a new layer of complexity in C. albicans adaptation, pathogenesis, and drug resistance. Such proteome plasticity is the result of a genetic code alteration where the leucine CUG codon is translated mainly as serine (97%), but maintains some level of leucine (3%) assignment. In this review, we dissect the link between C. albicans non-standard CUG translation, proteome plasticity, host adaptation and pathogenesis. We discuss published work showing how this pathogen uses the fidelity of protein synthesis to spawn novel virulence traits.
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Affiliation(s)
- Ana Rita Bezerra
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Carla Oliveira
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Inês Correia
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Ana Rita Guimarães
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Gonçalo Sousa
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Maria João Carvalho
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Gabriela Moura
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Manuel A S Santos
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
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18
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Villa S, Hamideh M, Weinstock A, Qasim MN, Hazbun TR, Sellam A, Hernday AD, Thangamani S. Transcriptional control of hyphal morphogenesis in Candida albicans. FEMS Yeast Res 2021; 20:5715912. [PMID: 31981355 PMCID: PMC7000152 DOI: 10.1093/femsyr/foaa005] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/31/2020] [Indexed: 12/12/2022] Open
Abstract
Candida albicans is a multimorphic commensal organism and opportunistic fungal pathogen in humans. A morphological switch between unicellular budding yeast and multicellular filamentous hyphal growth forms plays a vital role in the virulence of C. albicans, and this transition is regulated in response to a range of environmental cues that are encountered in distinct host niches. Many unique transcription factors contribute to the transcriptional regulatory network that integrates these distinct environmental cues and determines which phenotypic state will be expressed. These hyphal morphogenesis regulators have been extensively investigated, and represent an increasingly important focus of study, due to their central role in controlling a key C. albicans virulence attribute. This review provides a succinct summary of the transcriptional regulatory factors and environmental signals that control hyphal morphogenesis in C. albicans.
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Affiliation(s)
- Sonia Villa
- Masters in Biomedical Science Program, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| | - Mohammad Hamideh
- Masters in Biomedical Science Program, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| | - Anthony Weinstock
- Arizona College of Osteopathic Medicine, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| | - Mohammad N Qasim
- Quantitative and Systems Biology Graduate Program, School of Natural Sciences, University of California, Merced, Merced, CA, 95343, USA
| | - Tony R Hazbun
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA
| | - Adnane Sellam
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
| | - Aaron D Hernday
- Quantitative and Systems Biology Graduate Program, School of Natural Sciences, University of California, Merced, Merced, CA, 95343, USA.,Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, CA, 95343, USA
| | - Shankar Thangamani
- Department of Pathology and Population Medicine, College of Veterinary Medicine, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
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19
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Wang D, An N, Yang Y, Yang X, Fan Y, Feng J. Candida tropicalis distribution and drug resistance is correlated with ERG11 and UPC2 expression. Antimicrob Resist Infect Control 2021; 10:54. [PMID: 33722286 PMCID: PMC7958445 DOI: 10.1186/s13756-021-00890-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 01/11/2021] [Indexed: 12/15/2022] Open
Abstract
Background Candida tropicalis (C. tropicalis) is an important opportunistic pathogenic Candida species that can cause nosocomial infection. In this study, we analyzed the distribution and drug susceptibility of C. tropicalis and the relationship between ERG11 and UPC2 expression and resistance to azole antifungal agents. Methods C. tropicalis was cultured and identified by Sabouraud Agar Medium, CHROM Agar Candida and ATB tests (Bio-Mérieux, France). Total RNA was extracted from the collected strains, and the ERG11 and UPC2 mRNA expression levels were analyzed by quantitative real-time PCR. Results In total, 2872 clinical isolates of Candida, including 319 strains of C. tropicalis, were analyzed herein; they were mainly obtained from the Departments of Respiratory Medicine and ICU. The strains were predominantly isolated from airway secretion samples, and the detection trend in four years was mainly related to the type of department and specimens. The resistance rates of C. tropicalis to fluconazole, itraconazole and voriconazole had been increasing year by year. The mRNA expression levels of ERG11 and UPC2 in the fluconazole-resistant group were significantly higher than they were in the susceptible group. In addition, there was a significant positive linear correlation between these two genes in the fluconazole-resistant group. Conclusions Overexpression of the ERG11 and UPC2 genes in C. tropicalis could increase resistance to azole antifungal drugs. The routine testing for ERG11 and UPC2 in high-risk patients in key departments would provide a theoretical basis for the rational application of azole antifungal drugs.
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Affiliation(s)
- Dan Wang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chengdu Medical College, Chengdu, 610500, Sichuan Province, China
| | - Na An
- Department of Laboratory Medicine, Mianyang Central Hospital, Mianyang, 621000, Sichuan Province, China
| | - Yuwei Yang
- Department of Laboratory Medicine, Mianyang Central Hospital, Mianyang, 621000, Sichuan Province, China
| | - Xianggui Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chengdu Medical College, Chengdu, 610500, Sichuan Province, China
| | - Yingzi Fan
- Department of Laboratory Medicine, The First Affiliated Hospital of Chengdu Medical College, Chengdu, 610500, Sichuan Province, China
| | - Jiafu Feng
- Department of Laboratory Medicine, Mianyang Central Hospital, Mianyang, 621000, Sichuan Province, China.
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20
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Rai LS, Wijlick LV, Bougnoux ME, Bachellier-Bassi S, d'Enfert C. Regulators of commensal and pathogenic life-styles of an opportunistic fungus-Candida albicans. Yeast 2021; 38:243-250. [PMID: 33533498 DOI: 10.1002/yea.3550] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
The yeast Candida albicans is primarily a commensal of humans that colonizes the mucosal surfaces of the gastrointestinal and genital tracts. Yet, C. albicans can under certain circumstances undergo a shift from commensalism to pathogenicity. This transition is governed by fungal factors such as morphological transitions, environmental cues for instance relationships with gut microbiota and the host immune system. C. albicans utilizes distinct sets of regulatory programs to colonize or infect its host and to evade the host defense systems. Moreover, an orchestrated iron acquisition mechanism operates to adapt to specific niches with variable iron availability. Studies on regulatory networks and morphogenesis of these two distinct modes of C. albicans growth, suggest that both yeast and hyphal forms exist in both growth patterns and the regulatory circuits are inter-connected. Here, we summarize current knowledge about C. albicans commensal-to-pathogen shift, its regulatory elements and their contribution to human disease.
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Affiliation(s)
- Laxmi Shanker Rai
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France
| | - Lasse Van Wijlick
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France.,Unité de Parasitologie-Mycologie, Service de Microbiologie Clinique, Hôpital Necker-Enfants-Malades, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France
| | | | - Christophe d'Enfert
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France
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21
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Camphor and Eucalyptol-Anticandidal Spectrum, Antivirulence Effect, Efflux Pumps Interference and Cytotoxicity. Int J Mol Sci 2021; 22:ijms22020483. [PMID: 33418931 PMCID: PMC7825113 DOI: 10.3390/ijms22020483] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 12/27/2022] Open
Abstract
Candidaalbicans represents one of the most common fungal pathogens. Due to its increasing incidence and the poor efficacy of available antifungals, finding novel antifungal molecules is of great importance. Camphor and eucalyptol are bioactive terpenoid plant constituents and their antifungal properties have been explored previously. In this study, we examined their ability to inhibit the growth of different Candida species in suspension and biofilm, to block hyphal transition along with their impact on genes encoding for efflux pumps (CDR1 and CDR2), ergosterol biosynthesis (ERG11), and cytotoxicity to primary liver cells. Camphor showed excellent antifungal activity with a minimal inhibitory concentration of 0.125-0.35 mg/mL while eucalyptol was active in the range of 2-23 mg/mL. The results showed camphor's potential to reduce fungal virulence traits, that is, biofilm establishment and hyphae formation. On the other hand, camphor and eucalyptol treatments upregulated CDR1;CDR2 was positively regulated after eucalyptol application while camphor downregulated it. Neither had an impact on ERG11 expression. The beneficial antifungal activities of camphor were achieved with an amount that was non-toxic to porcine liver cells, making it a promising antifungal compound for future development. The antifungal concentration of eucalyptol caused cytotoxic effects and increased expression of efflux pump genes, which suggests that it is an unsuitable antifungal candidate.
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22
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Ivanov M, Kannan A, Stojković DS, Glamočlija J, Calhelha RC, Ferreira ICFR, Sanglard D, Soković M. Flavones, Flavonols, and Glycosylated Derivatives-Impact on Candida albicans Growth and Virulence, Expression of CDR1 and ERG11, Cytotoxicity. Pharmaceuticals (Basel) 2020; 14:ph14010027. [PMID: 33396973 PMCID: PMC7824033 DOI: 10.3390/ph14010027] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 12/15/2022] Open
Abstract
Due to the high incidence of fungal infections worldwide, there is an increasing demand for the development of novel therapeutic approaches. A wide range of natural products has been extensively studied, with considerable focus on flavonoids. The antifungal capacity of selected flavones (luteolin, apigenin), flavonols (quercetin), and their glycosylated derivatives (quercitrin, isoquercitrin, rutin, and apigetrin) along with their impact on genes encoding efflux pumps (CDR1) and ergosterol biosynthesis enzyme (ERG11) has been the subject of this study. Cytotoxicity of flavonoids towards primary liver cells has also been addressed. Luteolin, quercitrin, isoquercitrin, and rutin inhibited growth of Candida albicans with the minimal inhibitory concentration of 37.5 µg/mL. The application of isoquercitrin has reduced C. albicans biofilm establishing capacities for 76%, and hyphal formation by yeast. In vitro treatment with apigenin, apigetrin, and quercitrin has downregulated CDR1. Contrary to rutin and apigenin, isoquercitrin has upregulated ERG11. Except apigetrin and quercitrin (90 µg/mL and 73 µg/mL, respectively inhibited 50% of the net cell growth), the examined flavonoids did not exhibit cytotoxicity. The reduction of both fungal virulence and expression of antifungal resistance-linked genes was the most pronounced for apigenin and apigetrin; these results indicate flavonoids’ indispensable capacity for further development as part of an anticandidal therapy or prevention strategy.
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Affiliation(s)
- Marija Ivanov
- Department of Plant Physiology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia; (M.I.); (D.S.S.); (J.G.)
| | - Abhilash Kannan
- Institute of Microbiology, University Hospital Lausanne and University Hospital Center, Rue du Bugnon 48, 1011 Lausanne, Switzerland; (A.K.); (D.S.)
| | - Dejan S. Stojković
- Department of Plant Physiology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia; (M.I.); (D.S.S.); (J.G.)
| | - Jasmina Glamočlija
- Department of Plant Physiology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia; (M.I.); (D.S.S.); (J.G.)
| | - Ricardo C. Calhelha
- Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal; (R.C.C.); (I.C.F.R.F.)
| | - Isabel C. F. R. Ferreira
- Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal; (R.C.C.); (I.C.F.R.F.)
| | - Dominique Sanglard
- Institute of Microbiology, University Hospital Lausanne and University Hospital Center, Rue du Bugnon 48, 1011 Lausanne, Switzerland; (A.K.); (D.S.)
| | - Marina Soković
- Department of Plant Physiology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia; (M.I.); (D.S.S.); (J.G.)
- Correspondence:
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23
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Interaction of Styrylpyridinium Compound with Pathogenic Candida albicans Yeasts and Human Embryonic Kidney HEK-293 Cells. Microorganisms 2020; 9:microorganisms9010048. [PMID: 33375480 PMCID: PMC7823387 DOI: 10.3390/microorganisms9010048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/26/2022] Open
Abstract
Candida albicans-caused local and systemic diseases are a serious health issue worldwide, leading to high mycosis-associated morbidity and mortality. Efficient combinations of novel compounds with commonly used antifungals could be an important tool for fighting infections. The aim of this study was to evaluate the interaction of synthesized 4-(4-cyanostyryl)-1-dodecylpyridin-1-ium (CSDP+) bromide alone or in combination with fluconazole with yeast and mammalian cells. We investigated cytotoxicity of the tested agents to mammalian HEK-293 cells and the influence of CSDP+ on the ability of C. albicans wt and a clinical isolate to adhere to HEK-293. Accumulation of lipophilic cation ethidium (Et+) was used to monitor the activity of efflux pumps in HEK-293 cells. The effect of CSDP+ on the expression of the main efflux transporter genes and transcription factors in C.albicans cells as well as HEK-293 efflux pump gene ABCB1 was determined. The study showed that CSDP+ alone and in combination with fluconazole was nontoxic to HEK-293 cells and was able to reduce C.albicans adhesion. The treatment of C.albicans cells with CSDP+ in combination with fluconazole resulted in a considerable overexpression of the MDR1 and MRR1 genes. The findings suggest that these genes could be associated with efflux-related resistance to fluconazole. Measurements of Et+ fluorescence and analysis of ABCB1 gene expression demonstrated that mammalian cells were not sensitive to concentrations of CSDP+ affecting C. albicans.
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24
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Kim DW, Shin YK, Lee SW, Wimonmuang K, Kang KB, Lee YS, Yun SH. FgPKS7 is an essential player in mating-type-mediated regulatory pathway required for completing sexual cycle in Fusarium graminearum. Environ Microbiol 2020; 23:1972-1990. [PMID: 33169919 DOI: 10.1111/1462-2920.15305] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/03/2020] [Indexed: 12/01/2022]
Abstract
Secondary metabolism is intimately linked to developmental processes in filamentous fungi. In a previous study, we revealed that several polyketide synthase (PKS) genes, including FgPKS7, are specifically induced during formation of the sexual fruiting body (perithecium) in the cereal pathogen Fusarium graminearum. The function of PKS7, which is essential for perithecial development and hyphal growth, is interchangeable between two phylogenetically related species, F. graminearum and F. asiaticum, but not conserved in the more distantly related species F. fujikuroi and F. neocosmosporiellum. FgPKS7 is under the control of global or upstream regulators including the mating-type (MAT) locus and regulates numerous downstream genes that are transcriptionally specific to and functionally essential for sexual development, several other PKS genes, and ABC transporter genes for azole resistance in F. graminearum. FgPKS7 is an essential element for proper sexual development and participates in a regulatory network controlled by the MAT locus. Although the chemical identity of FgPKS7 remains unclear, FgPKS7 is likely involved in chemical reaction(s) for synthesis of metabolite(s) that control or promote perithecial maturation in F. graminearum. This study provides in-depth insights into the direct role of secondary metabolites in sexual development of filamentous fungi.
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Affiliation(s)
- Da-Woon Kim
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Republic of Korea
| | - Yoo-Kyoung Shin
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Republic of Korea
| | - Sang-Won Lee
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Republic of Korea
| | - Kanphassorn Wimonmuang
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Republic of Korea
| | - Kyo Bin Kang
- College of Pharmacy, Sookmyung Women's University, Seoul, 04310, Republic of Korea
| | - Young-Sang Lee
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Republic of Korea
| | - Sung-Hwan Yun
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Republic of Korea
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25
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First Report of Candidemia Clonal Outbreak Caused by Emerging Fluconazole-Resistant Candida parapsilosis Isolates Harboring Y132F and/or Y132F+K143R in Turkey. Antimicrob Agents Chemother 2020; 64:AAC.01001-20. [PMID: 32690638 DOI: 10.1128/aac.01001-20] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/08/2020] [Indexed: 12/20/2022] Open
Abstract
Clonal outbreaks of fluconazole-resistant (FLZR) Candida parapsilosis isolates have been reported in several countries. Despite its being the second leading cause of candidemia, the azole resistance mechanisms and the clonal expansion of FLZR C. parapsilosis blood isolates have not been reported in Turkey. In this study, we consecutively collected C. parapsilosis blood isolates (n = 225) from the fifth largest hospital in Turkey (2007 to 2019), assessed their azole susceptibility pattern using CLSI M27-A3/S4, and sequenced ERG11 for all and MRR1, TAC1, and UPC2 for a selected number of C. parapsilosis isolates. The typing resolution of two widely used techniques, amplified fragment length polymorphism typing (AFLP) and microsatellite typing (MST), and the biofilm production of FLZR isolates with and without Y132F were compared. Approximately 27% of isolates were FLZR (60/225), among which 90% (54/60) harbored known mutations in Erg11, including Y132F (24/60) and Y132F+K143R (19/60). Several mutations specific to FLZR isolates were found in MRR1, TAC1, and UPC2 AFLP grouped isolates into two clusters, while MST revealed several clusters. The majority of Y132F/Y132F+K143R isolates grouped in clonal clusters, which significantly expanded throughout 2007 to 2019 in neonatal wards. Candida parapsilosis isolates carrying Y132F were associated with significantly higher mortality and less biofilm production than other FLZR isolates. Collectively, we documented the first outbreak of FLZR C. parapsilosis blood isolates in Turkey. The MRR1, TAC1, and UPC2 mutations exclusively found in FLZR isolates establishes a basis for future studies, which will potentially broaden our knowledge of FLZR mechanisms in C. parapsilosis MST should be a preferred method for clonal analysis of C. parapsilosis isolates in outbreak scenarios.
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26
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Bhattacharya S, Sae-Tia S, Fries BC. Candidiasis and Mechanisms of Antifungal Resistance. Antibiotics (Basel) 2020; 9:antibiotics9060312. [PMID: 32526921 PMCID: PMC7345657 DOI: 10.3390/antibiotics9060312] [Citation(s) in RCA: 200] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/06/2020] [Accepted: 06/07/2020] [Indexed: 12/13/2022] Open
Abstract
Candidiasis can be present as a cutaneous, mucosal or deep-seated organ infection, which is caused by more than 20 types of Candida sp., with C. albicans being the most common. These are pathogenic yeast and are usually present in the normal microbiome. High-risk individuals are patients of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), organ transplant, and diabetes. During infection, pathogens can adhere to complement receptors and various extracellular matrix proteins in the oral and vaginal cavity. Oral and vaginal Candidiasis results from the overgrowth of Candida sp. in the hosts, causing penetration of the oral and vaginal tissues. Symptoms include white patches in the mouth, tongue, throat, and itchiness or burning of genitalia. Diagnosis involves visual examination, microscopic analysis, or culturing. These infections are treated with a variety of antifungals that target different biosynthetic pathways of the pathogen. For example, echinochandins target cell wall biosynthesis, while allylamines, azoles, and morpholines target ergosterol biosynthesis, and 5-Flucytosine (5FC) targets nucleic acid biosynthesis. Azoles are commonly used in therapeutics, however, because of its fungistatic nature, Candida sp. evolve azole resistance. Besides azoles, Candida sp. also acquire resistance to polyenes, echinochandins, and 5FC. This review discusses, in detail, the drug resistance mechanisms adapted by Candida sp.
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Affiliation(s)
- Somanon Bhattacharya
- Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA; (S.S.-T.); (B.C.F.)
- Correspondence:
| | - Sutthichai Sae-Tia
- Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA; (S.S.-T.); (B.C.F.)
| | - Bettina C. Fries
- Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA; (S.S.-T.); (B.C.F.)
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, NY 11794, USA
- Veterans Administration Medical Center, Northport, New York, NY 11768, USA
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27
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Oliveira JSD, Pereira VS, Castelo-Branco DDSCM, Cordeiro RDA, Sidrim JJC, Brilhante RSN, Rocha MFG. The yeast, the antifungal, and the wardrobe: a journey into antifungal resistance mechanisms of Candida tropicalis. Can J Microbiol 2020; 66:377-388. [PMID: 32319304 DOI: 10.1139/cjm-2019-0531] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Candida tropicalis is a prominent non-Candida albicans Candida species involved in cases of candidemia, mainly causing infections in patients in intensive care units and (or) those presenting neutropenia. In recent years, several studies have reported an increase in the recovery rates of azole-resistant C. tropicalis isolates. Understanding C. tropicalis resistance is of great importance, since resistant strains are implicated in persistent or recurrent and breakthrough infections. In this review, we address the main mechanisms underlying C. tropicalis resistance to the major antifungal classes used to treat candidiasis. The main genetic basis involved in C. tropicalis antifungal resistance is discussed. A better understanding of the epidemiology of resistant strains and the mechanisms involved in C. tropicalis resistance can help improve diagnosis and assessment of the antifungal susceptibility of this Candida species to improve clinical management.
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Affiliation(s)
- Jonathas Sales de Oliveira
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil
| | - Vandbergue Santos Pereira
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil
| | - Débora de Souza Collares Maia Castelo-Branco
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil
| | - Rossana de Aguiar Cordeiro
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil
| | - José Júlio Costa Sidrim
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil
| | - Raimunda Sâmia Nogueira Brilhante
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil
| | - Marcos Fábio Gadelha Rocha
- Department of Pathology and Legal Medicine, School of Medicine, Specialized Medical Mycology Center, Graduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza-CE, Brazil.,School of Veterinary, Postgraduate Program in Veterinary Sciences, State University of Ceará, 1315 Coronel Nunes de Melo Street, Rodolfo Teófilo, CEP 60420-270, Fortaleza-CE, Brazil
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28
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Salazar SB, Simões RS, Pedro NA, Pinheiro MJ, Carvalho MFNN, Mira NP. An Overview on Conventional and Non-Conventional Therapeutic Approaches for the Treatment of Candidiasis and Underlying Resistance Mechanisms in Clinical Strains. J Fungi (Basel) 2020; 6:E23. [PMID: 32050673 PMCID: PMC7151124 DOI: 10.3390/jof6010023] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Fungal infections and, in particular, those caused by species of the Candida genus, are growing at an alarming rate and have high associated rates of mortality and morbidity. These infections, generally referred as candidiasis, range from common superficial rushes caused by an overgrowth of the yeasts in mucosal surfaces to life-threatening disseminated mycoses. The success of currently used antifungal drugs to treat candidiasis is being endangered by the continuous emergence of resistant strains, specially among non-albicans Candida species. In this review article, the mechanisms of action of currently used antifungals, with emphasis on the mechanisms of resistance reported in clinical isolates, are reviewed. Novel approaches being taken to successfully inhibit growth of pathogenic Candida species, in particular those based on the exploration of natural or synthetic chemicals or on the activity of live probiotics, are also reviewed. It is expected that these novel approaches, either used alone or in combination with traditional antifungals, may contribute to foster the identification of novel anti-Candida therapies.
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Affiliation(s)
- Sara B. Salazar
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Rita S. Simões
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Nuno A. Pedro
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Maria Joana Pinheiro
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Maria Fernanda N. N. Carvalho
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal;
| | - Nuno P. Mira
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
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29
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Delavy M, Cerutti L, Croxatto A, Prod'hom G, Sanglard D, Greub G, Coste AT. Machine Learning Approach for Candida albicans Fluconazole Resistance Detection Using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. Front Microbiol 2020; 10:3000. [PMID: 32010083 PMCID: PMC6971193 DOI: 10.3389/fmicb.2019.03000] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 12/11/2019] [Indexed: 12/16/2022] Open
Abstract
Candida albicans causes life-threatening systemic infections in immunosuppressed patients. These infections are commonly treated with fluconazole, an antifungal agent targeting the ergosterol biosynthesis pathway. Current Antifungal Susceptibility Testing (AFST) methods are time-consuming and are often subjective. Moreover, they cannot reliably detect the tolerance phenomenon, a breeding ground for the resistance. An alternative to the classical AFST methods could use Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass spectrometry (MS). This tool, already used in clinical microbiology for microbial species identification, has already offered promising results to detect antifungal resistance on non-azole tolerant yeasts. Here, we propose a machine-learning approach, adapted to MALDI-TOF MS data, to qualitatively detect fluconazole resistance in the azole tolerant species C. albicans. MALDI-TOF MS spectra were acquired from 33 C. albicans clinical strains isolated from 15 patients. Those strains were exposed for 3 h to 3 fluconazole concentrations (256, 16, 0 μg/mL) and with (5 μg/mL) or without cyclosporin A, an azole tolerance inhibitor, leading to six different experimental conditions. We then optimized a protein extraction protocol allowing the acquisition of high-quality spectra, which were further filtered through two quality controls. The first one consisted of discarding not identified spectra and the second one selected only the most similar spectra among replicates. Quality-controlled spectra were divided into six sets, following the sample preparation's protocols. Each set was then processed through an R based script using pre-defined housekeeping peaks allowing peak spectra positioning. Finally, 32 machine-learning algorithms applied on the six sets of spectra were compared, leading to 192 different pipelines of analysis. We selected the most robust pipeline with the best accuracy. This LDA model applied to the samples prepared in presence of tolerance inhibitor but in absence of fluconazole reached a specificity of 88.89% and a sensitivity of 83.33%, leading to an overall accuracy of 85.71%. Overall, this work demonstrated that combining MALDI-TOF MS and machine-learning could represent an innovative mycology diagnostic tool.
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Affiliation(s)
- Margot Delavy
- Microbiology Institute, University Hospital Lausanne, Lausanne, Switzerland
| | - Lorenzo Cerutti
- SmartGene Services, EPFL Innovation Park, Lausanne, Switzerland
| | - Antony Croxatto
- Microbiology Institute, University Hospital Lausanne, Lausanne, Switzerland
| | - Guy Prod'hom
- Microbiology Institute, University Hospital Lausanne, Lausanne, Switzerland
| | - Dominique Sanglard
- Microbiology Institute, University Hospital Lausanne, Lausanne, Switzerland
| | - Gilbert Greub
- Microbiology Institute, University Hospital Lausanne, Lausanne, Switzerland
| | - Alix T Coste
- Microbiology Institute, University Hospital Lausanne, Lausanne, Switzerland
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30
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Feng W, Yang J, Ji Y, Xi Z, Yang L, Zhu X, Ma Y. Mrr2
mutations and upregulation are associated with increased fluconazole resistance in
Candida albicans
isolates from patients with vulvovaginal candidiasis. Lett Appl Microbiol 2019; 70:95-101. [PMID: 31705810 DOI: 10.1111/lam.13248] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 11/26/2022]
Affiliation(s)
- W. Feng
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
| | - J. Yang
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
| | - Y. Ji
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
| | - Z. Xi
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
| | - L. Yang
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
| | - X. Zhu
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
| | - Y. Ma
- The Department of Dermatovenereology The Second Hospital of Shanxi Medical University Taiyuan Shanxi China
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31
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Fischer D, Gessner G, Fill TP, Barnett R, Tron K, Dornblut K, Kloss F, Stallforth P, Hube B, Heinemann SH, Hertweck C, Scherlach K, Brunke S. Disruption of Membrane Integrity by the Bacterium-Derived Antifungal Jagaricin. Antimicrob Agents Chemother 2019; 63:e00707-19. [PMID: 31235622 PMCID: PMC6709453 DOI: 10.1128/aac.00707-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/14/2019] [Indexed: 01/05/2023] Open
Abstract
Jagaricin is a lipopeptide produced by the bacterial mushroom pathogen Janthinobacterium agaricidamnosum, the causative agent of mushroom soft rot disease. Apart from causing lesions in mushrooms, jagaricin is a potent antifungal active against human-pathogenic fungi. We show that jagaricin acts by impairing membrane integrity, resulting in a rapid flux of ions, including Ca2+, into susceptible target cells. Accordingly, the calcineurin pathway is required for jagaricin tolerance in the fungal pathogen Candida albicans Transcriptional profiling of pathogenic yeasts further revealed that jagaricin triggers cell wall strengthening, general shutdown of membrane potential-driven transport, and the upregulation of lipid transporters, linking cell envelope integrity to jagaricin action and resistance. Whereas jagaricin shows hemolytic effects, it exhibited either no or low plant toxicity at concentrations at which the growth of prevalent phytopathogenic fungi is inhibited. Therefore, jagaricin may have potential for agricultural applications. The action of jagaricin as a membrane-disrupting antifungal is promising but would require modifications for use in humans.
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Affiliation(s)
- Daniel Fischer
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Guido Gessner
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Taicia Pacheco Fill
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Robert Barnett
- Junior Research Group Chemistry of Microbial Communication, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Kyrylo Tron
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Katharina Dornblut
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Florian Kloss
- Transfer Group Antiinfectives, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Pierre Stallforth
- Junior Research Group Chemistry of Microbial Communication, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Stefan H Heinemann
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Kirstin Scherlach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
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Shivarathri R, Tscherner M, Zwolanek F, Singh NK, Chauhan N, Kuchler K. The Fungal Histone Acetyl Transferase Gcn5 Controls Virulence of the Human Pathogen Candida albicans through Multiple Pathways. Sci Rep 2019; 9:9445. [PMID: 31263212 PMCID: PMC6603162 DOI: 10.1038/s41598-019-45817-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/14/2019] [Indexed: 12/28/2022] Open
Abstract
Fungal virulence is regulated by a tight interplay of transcriptional control and chromatin remodelling. Despite compelling evidence that lysine acetylation modulates virulence of pathogenic fungi such as Candida albicans, the underlying mechanisms have remained largely unexplored. We report here that Gcn5, a paradigm lysyl-acetyl transferase (KAT) modifying both histone and non-histone targets, controls fungal morphogenesis - a key virulence factor of C. albicans. Our data show that genetic removal of GCN5 abrogates fungal virulence in mice, suggesting strongly diminished fungal fitness in vivo. This may at least in part arise from increased susceptibility to killing by macrophages, as well as by other phagocytes such as neutrophils or monocytes. Loss of GCN5 also causes hypersensitivity to the fungicidal drug caspofungin. Caspofungin hypersusceptibility requires the master regulator Efg1, working in concert with Gcn5. Moreover, Gcn5 regulates multiple independent pathways, including adhesion, cell wall-mediated MAP kinase signaling, hypersensitivity to host-derived oxidative stress, and regulation of the Fks1 glucan synthase, all of which play critical roles in virulence and antifungal susceptibility. Hence, Gcn5 regulates fungal virulence through multiple mechanisms, suggesting that specific inhibition of Gcn5 could offer new therapeutic strategies to combat invasive fungal infections.
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Affiliation(s)
- Raju Shivarathri
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | - Michael Tscherner
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | - Florian Zwolanek
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | | | - Neeraj Chauhan
- Public Health Research Institute, New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ, 07103, USA.
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ, 07103, USA.
| | - Karl Kuchler
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria.
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Monk BC, Sagatova AA, Hosseini P, Ruma YN, Wilson RK, Keniya MV. Fungal Lanosterol 14α-demethylase: A target for next-generation antifungal design. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140206. [PMID: 30851431 DOI: 10.1016/j.bbapap.2019.02.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/15/2019] [Accepted: 02/21/2019] [Indexed: 12/19/2022]
Abstract
The cytochrome P450 enzyme lanosterol 14α-demethylase (LDM) is the target of the azole antifungals used widely in medicine and agriculture as prophylaxis or treatments of infections or diseases caused by fungal pathogens. These drugs and agrochemicals contain an imidazole, triazole or tetrazole substituent, with one of the nitrogens in the azole ring coordinating as the sixth axial ligand to the LDM heme iron. Structural studies show that this membrane bound enzyme contains a relatively rigid ligand binding pocket comprised of a deeply buried heme-containing active site together with a substrate entry channel and putative product exit channel that reach to the membrane. Within the ligand binding pocket the azole antifungals have additional affinity determining interactions with hydrophobic side-chains, the polypeptide backbone and via water-mediated hydrogen bond networks. This review will describe the tools that can be used to identify and characterise the next generation of antifungals targeting LDM, with the goal of obtaining highly potent broad-spectrum fungicides that will be able to avoid target and drug efflux mediated antifungal resistance.
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Affiliation(s)
- Brian C Monk
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
| | - Alia A Sagatova
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Parham Hosseini
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Yasmeen N Ruma
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Rajni K Wilson
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Mikhail V Keniya
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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Delavy M, Dos Santos AR, Heiman CM, Coste AT. Investigating Antifungal Susceptibility in Candida Species With MALDI-TOF MS-Based Assays. Front Cell Infect Microbiol 2019; 9:19. [PMID: 30792970 PMCID: PMC6375026 DOI: 10.3389/fcimb.2019.00019] [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: 11/01/2018] [Accepted: 01/22/2019] [Indexed: 12/21/2022] Open
Abstract
Half of invasive fungal infections lead to death. Amongst pathogenic fungi, the most widespread species belong to the Candida genus and vary in their susceptibility to antifungal drugs. The emergence of antifungal resistance has become a major clinical problem. Therefore, the definition of susceptibility patterns is crucial for the survival of patients and the monitoring of resistance epidemiology. Although, most routinely used methods of AntiFungal Susceptibility Testing (AFST) have reached their limits, the rediscovery of Matrix Associated Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) in the field of mycology provides a promising alternative for the study of antifungal resistance. MALDI-TOF MS is already used in mycology for fungal identification, which permits to highlight inherent antifungal resistance. However, the main concern of clinicians is the rise of acquired antifungal resistance and the time needed for their detection. For this purpose, MALDI-TOF MS has been shown to be an accurate tool for AFST, presenting numerous advantages in comparison to commonly used techniques. Finally, MALDI-TOF MS could be used directly to detect resistance mechanisms through typing. Consequently, MALDI-TOF MS offers new perspectives in the context of healthcare associated outbreaks of emerging multi-drug resistant fungi, such as C. auris. As a proof of concept, we will illustrate the current and future benefits in using and adapting MALDI-TOF MS-based assays to define the susceptibility pattern of C. auris, by species identification, AFST, and typing.
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Affiliation(s)
- Margot Delavy
- Institute of Microbiology, University of Lausanne and University Hospital of Lausanne, Lausanne, Switzerland
| | - Andrea R Dos Santos
- Institute of Microbiology, University of Lausanne and University Hospital of Lausanne, Lausanne, Switzerland
| | - Clara M Heiman
- Institute of Microbiology, University of Lausanne and University Hospital of Lausanne, Lausanne, Switzerland
| | - Alix T Coste
- Institute of Microbiology, University of Lausanne and University Hospital of Lausanne, Lausanne, Switzerland
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Evolution of Fluconazole-Resistant Candida albicans Strains by Drug-Induced Mating Competence and Parasexual Recombination. mBio 2019; 10:mBio.02740-18. [PMID: 30723130 PMCID: PMC6428756 DOI: 10.1128/mbio.02740-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Sexual reproduction is an important mechanism in the evolution of species, since it allows the combination of advantageous traits of individual members in a population. The pathogenic yeast Candida albicans is a diploid organism that normally propagates in a clonal fashion, because heterozygosity at the mating type locus (MTL) inhibits mating between cells. Here we show that C. albicans cells that have acquired drug resistance mutations during treatment with the commonly used antifungal agent fluconazole rapidly develop further increased resistance by genome rearrangements that result in simultaneous loss of heterozygosity for the mutated allele and the mating type locus. This enables the drug-resistant cells of a population to switch to the mating-competent opaque morphology and mate with each other to combine different individually acquired resistance mechanisms. The tetraploid mating products reassort their merged genomes and, under selective pressure by the drug, generate highly resistant progeny that have retained the advantageous mutated alleles. Parasexual propagation, promoted by stress-induced genome rearrangements that result in the acquisition of mating competence in cells with adaptive mutations, may therefore be an important mechanism in the evolution of C. albicans populations. The clonal population structure of Candida albicans suggests that (para)sexual recombination does not play an important role in the lifestyle of this opportunistic fungal pathogen, an assumption that is strengthened by the fact that most C. albicans strains are heterozygous at the mating type locus (MTL) and therefore mating-incompetent. On the other hand, mating might occur within clonal populations and allow the combination of advantageous traits that were acquired by individual cells to adapt to adverse conditions. We have investigated if parasexual recombination may be involved in the evolution of highly drug-resistant strains exhibiting multiple resistance mechanisms against fluconazole, an antifungal drug that is commonly used to treat infections by C. albicans. Growth of strains that were heterozygous for MTL and different fluconazole resistance mutations in the presence of the drug resulted in the emergence of derivatives that had become homozygous for the mutated allele and the mating type locus and exhibited increased drug resistance. When MTLa/a and MTLα/α cells of these strains were mixed in all possible combinations, we could isolate mating products containing the genetic material from both parents. The initial mating products did not exhibit higher drug resistance than their parental strains, but further propagation under selective pressure resulted in the loss of the wild-type alleles and increased fluconazole resistance. Therefore, fluconazole treatment not only selects for resistance mutations but also promotes genomic alterations that confer mating competence, which allows cells in an originally clonal population to exchange individually acquired resistance mechanisms and generate highly drug-resistant progeny.
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Ravasi D, König R, Principi P, Perale G, Demarta A. Effect of Powdered Activated Carbon as Advanced Step in Wastewater Treatments on Antibiotic Resistant Microorganisms. Curr Pharm Biotechnol 2019; 20:63-75. [PMID: 30727884 PMCID: PMC6637097 DOI: 10.2174/1389201020666190207095556] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/16/2018] [Accepted: 01/19/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Conventional wastewater treatment plants discharge significant amounts of antibiotic resistant bacteria and antibiotic resistance genes into natural water bodies contributing to the spread of antibiotic resistance. Some advanced wastewater treatment technologies have been shown to effectively decrease the number of bacteria. Nevertheless, there is still a lack of knowledge about the effectiveness of these treatments on antibiotic resistant bacteria and antibiotic resistant genes. To the best of our knowledge, no specific studies have considered how powdered activated carbon (PAC) treatments can act on antibiotic resistant bacteria, although it is essential to assess the impact of this wastewater treatment on the spread of antibiotic resistant bacteria. METHODS To address this gap, we evaluated the fate and the distribution of fluorescent-tagged antibiotic/ antimycotic resistant microorganisms in a laboratory-scale model simulating a process configuration involving powdered activated carbon as advanced wastewater treatment. Furthermore, we studied the possible increase of naturally existing antibiotic resistant bacteria during the treatment implementing PAC recycling. RESULTS The analysis of fluorescent-tagged microorganisms demonstrated the efficacy of the PAC adsorption treatment in reducing the load of both susceptible and resistant fluorescent microorganisms in the treated water, reaching a removal efficiency of 99.70%. Moreover, PAC recycling did not increase the resistance characteristics of cultivable bacteria neither in the sludge nor in the treated effluent. CONCLUSION Results suggest that wastewater PAC treatment is a promising technology not only for the removal of micropollutants but also for its effect in decreasing antibiotic resistant bacteria release.
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Affiliation(s)
| | | | | | | | - Antonella Demarta
- Address correspondence to this author at the Laboratory of applied microbiology, Department of Environment, Construction and Design, University of Applied Sciences and Arts of Southern Switzerland, Via Mirasole 22a, 6501 Bellinzona, Switzerland; E-mail:
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Efflux pump-mediated resistance to antifungal compounds can be prevented by conjugation with triphenylphosphonium cation. Nat Commun 2018; 9:5102. [PMID: 30504815 PMCID: PMC6269435 DOI: 10.1038/s41467-018-07633-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 11/13/2018] [Indexed: 11/21/2022] Open
Abstract
Antifungal resistance due to upregulation of efflux pumps is prevalent in clinical Candida isolates. Potential efflux pump substrates (PEPSs), which are active against strains deficient in efflux pumps but inactive against wild-type strains, are usually missed in routine antifungal screening. Here we present a method for identification of PEPSs, and show that conjugation with mitochondria-targeting triphenylphosphonium cation (TPP+) can enhance or restore the compounds’ antifungal activity. The screening method involves co-culturing a wild-type C. albicans strain and a Cdr efflux pump-deficient strain, labelled with different fluorescent proteins. We identify several PEPSs from a library of natural terpenes, and restore their antifungal activity against wild-type and azole-resistant C. albicans by conjugation with TPP+. The most active conjugate (IS-2-Pi-TPP) kills C. albicans cells, prevents biofilm formation and eliminates preformed biofilms, without inducing significant resistance. The antifungal activity is accompanied by mitochondrial dysfunction and increased levels of intracellular reactive oxygen species. In addition, IS-2-Pi-TPP is effective against C. albicans in a mouse model of skin infection. Antifungal resistance due to upregulation of efflux pumps is common in Candida albicans. Here, the authors show that conjugation with mitochondria-targeting triphenylphosphonium cation can enhance or restore the antifungal activity of potential efflux pump substrates.
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A Hyperactive Form of the Zinc Cluster Transcription Factor Stb5 Causes YOR1 Overexpression and Beauvericin Resistance in Candida albicans. Antimicrob Agents Chemother 2018; 62:AAC.01655-18. [PMID: 30249688 DOI: 10.1128/aac.01655-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/14/2018] [Indexed: 11/20/2022] Open
Abstract
Gain-of-function mutations in the zinc cluster transcription factors Mrr1, Tac1, and Upc2, which result in constitutive overexpression of their target genes, are a frequent cause of fluconazole resistance in the pathogenic yeast Candida albicans In this study, we show that an activated form of another zinc cluster transcription factor, Stb5, confers resistance to the natural compound beauvericin via the overexpression of YOR1, encoding an efflux pump of the ATP-binding cassette transporter superfamily. Beauvericin was recently shown to potentiate the activity of azole drugs against C. albicans Although Yor1 did not contribute to fluconazole resistance when C. albicans cells were treated with the drug alone, Stb5-mediated YOR1 overexpression diminished the synergistic effect of the fluconazole-beauvericin combination, thereby enhancing fluconazole resistance in beauvericin-treated C. albicans cells. Stb5-mediated YOR1 overexpression also suppressed the inhibition of hyphal growth, an important virulence trait of C. albicans, by beauvericin. Therefore, activating mutations in Stb5, which result in constitutive YOR1 overexpression, may enable C. albicans to acquire resistance to beauvericin and thereby overcome both the sensitization to azole drugs and the inhibition of morphogenesis caused by this compound.
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Hawkins NJ, Fraaije BA. Fitness Penalties in the Evolution of Fungicide Resistance. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:339-360. [PMID: 29958074 DOI: 10.1146/annurev-phyto-080417-050012] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The evolution of resistance poses an ongoing threat to crop protection. Fungicide resistance provides a selective advantage under fungicide selection, but resistance-conferring mutations may also result in fitness penalties, resulting in an evolutionary trade-off. These penalties may result from the functional constraints of an evolving target site or from the resource allocation costs of overexpression or active transport. The extent to which such fitness penalties are present has important implications for resistance management strategies, determining whether resistance persists or declines between treatments, and for resistance risk assessments for new modes of action. Experimental results have proven variable, depending on factors such as temperature, nutrient status, osmotic or oxidative stress, and pathogen life-cycle stage. Functional genetics tools allow pathogen genetic background to be controlled, but this in turn raises the question of epistatic interactions. Combining fitness penalties under various conditions into a field-realistic scenario poses an important future challenge.
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Affiliation(s)
- N J Hawkins
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom;
| | - B A Fraaije
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom;
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Kakade P, Mahadik K, Balaji KN, Sanyal K, Nagaraja V. Two negative regulators of biofilm development exhibit functional divergence in conferring virulence potential toCandida albicans. FEMS Yeast Res 2018; 19:5057869. [DOI: 10.1093/femsyr/foy078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/12/2018] [Indexed: 01/08/2023] Open
Affiliation(s)
- Pallavi Kakade
- Department of Microbiology and Cell Biology, Indian Institute of Science, C V Raman Avenue, New Biological Sciences Building, Bangalore 560012, India
| | - Kasturi Mahadik
- Department of Microbiology and Cell Biology, Indian Institute of Science, C V Raman Avenue, New Biological Sciences Building, Bangalore 560012, India
| | - Kithiganahalli Narayanaswamy Balaji
- Department of Microbiology and Cell Biology, Indian Institute of Science, C V Raman Avenue, New Biological Sciences Building, Bangalore 560012, India
| | - Kaustuv Sanyal
- Department of Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, C V Raman Avenue, New Biological Sciences Building, Bangalore 560012, India
- Department of Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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Lara HH, Guisbiers G, Mendoza J, Mimun LC, Vincent BA, Lopez-Ribot JL, Nash KL. Synergistic antifungal effect of chitosan-stabilized selenium nanoparticles synthesized by pulsed laser ablation in liquids against Candida albicans biofilms. Int J Nanomedicine 2018; 13:2697-2708. [PMID: 29760550 PMCID: PMC5937483 DOI: 10.2147/ijn.s151285] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Candida albicans is a major opportunistic fungal pathogen. One of the most important virulence factors that contribute to the pathogenesis of candidiasis is its ability to form biofilms. A key characteristic of Candida biofilms is their resistance to antifungal agents. Due to significant morbidity and mortality rates related to biofilm-associated drug resistance, there is an urgency to develop novel nanotechnology-based approaches preventing biofilm-related infections. METHODS In this study, we report, for the first time, the synthesis of selenium nanoparticles by irradiating selenium pellets by nanosecond pulsed laser ablation in liquid chitosan as a capping agent. Synergy of the fungicidal effect of selenium nanoparticles and chitosan was quantified by the combination index theorem of Chou-Talalay. RESULTS This drug combination resulted in a potent fungicidal effect against a preformed C. albicans biofilm in a dose-response manner. By advanced electron microscopy techniques, we documented the adhesive and permeabilizing properties of chitosan, therefore allowing selenium nanoparticles to enter as the cell wall of the yeast became disrupted and distorted. Most importantly, we demonstrated a potent quantitative synergistic effect when compounds such as selenium and chitosan are combined. CONCLUSION These chitosan-stabilized selenium nanoparticles could be used for ex vivo applications such as sterilizers for surfaces and biomedical devices.
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Affiliation(s)
- Humberto H Lara
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Gregory Guisbiers
- Department of Physics and Astronomy, University of Arkansas at Little Rock, Little Rock, AR, USA
| | - Jonathan Mendoza
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Lawrence C Mimun
- US Army Engineer Research & Development Center, Vicksburg, MS, USA
| | - Brandy A Vincent
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Jose L Lopez-Ribot
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Kelly L Nash
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, TX, USA
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Rapid Phenotypic and Genotypic Diversification After Exposure to the Oral Host Niche in Candida albicans. Genetics 2018; 209:725-741. [PMID: 29724862 DOI: 10.1534/genetics.118.301019] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/21/2018] [Indexed: 12/15/2022] Open
Abstract
In vitro studies suggest that stress may generate random standing variation and that different cellular and ploidy states may evolve more rapidly under stress. Yet this idea has not been tested with pathogenic fungi growing within their host niche in vivo Here, we analyzed the generation of both genotypic and phenotypic diversity during exposure of Candida albicans to the mouse oral cavity. Ploidy, aneuploidy, loss of heterozygosity (LOH), and recombination were determined using flow cytometry and double digest restriction site-associated DNA sequencing. Colony phenotypic changes in size and filamentous growth were evident without selection and were enriched among colonies selected for LOH of the GAL1 marker. Aneuploidy and LOH occurred on all chromosomes (Chrs), with aneuploidy more frequent for smaller Chrs and whole Chr LOH more frequent for larger Chrs. Large genome shifts in ploidy to haploidy often maintained one or more heterozygous disomic Chrs, consistent with random Chr missegregation events. Most isolates displayed several different types of genomic changes, suggesting that the oral environment rapidly generates diversity de novo In sharp contrast, following in vitro propagation, isolates were not enriched for multiple LOH events, except in those that underwent haploidization and/or had high levels of Chr loss. The frequency of events was overall 100 times higher for C. albicans populations following in vivo passage compared with in vitro These hyper-diverse in vivo isolates likely provide C. albicans with the ability to adapt rapidly to the diversity of stress environments it encounters inside the host.
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Hampe IAI, Friedman J, Edgerton M, Morschhäuser J. An acquired mechanism of antifungal drug resistance simultaneously enables Candida albicans to escape from intrinsic host defenses. PLoS Pathog 2017; 13:e1006655. [PMID: 28953977 PMCID: PMC5633205 DOI: 10.1371/journal.ppat.1006655] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/09/2017] [Accepted: 09/19/2017] [Indexed: 12/23/2022] Open
Abstract
The opportunistic fungal pathogen Candida albicans frequently produces genetically altered variants to adapt to environmental changes and new host niches in the course of its life-long association with the human host. Gain-of-function mutations in zinc cluster transcription factors, which result in the constitutive upregulation of their target genes, are a common cause of acquired resistance to the widely used antifungal drug fluconazole, especially during long-term therapy of oropharyngeal candidiasis. In this study, we investigated if C. albicans also can develop resistance to the antimicrobial peptide histatin 5, which is secreted in the saliva of humans to protect the oral mucosa from pathogenic microbes. As histatin 5 has been shown to be transported out of C. albicans cells by the Flu1 efflux pump, we screened a library of C. albicans strains that contain artificially activated forms of all zinc cluster transcription factors of this fungus for increased FLU1 expression. We found that a hyperactive Mrr1, which confers fluconazole resistance by upregulating the multidrug efflux pump MDR1 and other genes, also causes FLU1 overexpression. Similarly to the artificially activated Mrr1, naturally occurring gain-of-function mutations in this transcription factor also caused FLU1 upregulation and increased histatin 5 resistance. Surprisingly, however, Mrr1-mediated histatin 5 resistance was mainly caused by the upregulation of MDR1 instead of FLU1, revealing a previously unrecognized function of the Mdr1 efflux pump. Fluconazole-resistant clinical C. albicans isolates with different Mrr1 gain-of-function mutations were less efficiently killed by histatin 5, and this phenotype was reverted when MRR1 was deleted. Therefore, antimycotic therapy can promote the evolution of strains that, as a consequence of drug resistance mutations, simultaneously have acquired increased resistance against an innate host defense mechanism and are thereby better adapted to certain host niches. The yeast Candida albicans is part of the normal microflora of most healthy persons, but it can also cause symptomatic infections when host defenses are compromised. C. albicans frequently generates genetically altered variants that are better adapted to changes in its environment during colonization and infection. We investigated if C. albicans can evolve resistance to histatin 5 (Hst 5), an antimicrobial peptide that is produced in the saliva of humans and protects the oral cavity against this pathogen. We found that activated forms of the transcription factor Mrr1 reduce the susceptibility of C. albicans to killing by Hst 5, a phenotype that was partially caused by Mrr1-mediated overexpression of the multidrug efflux pump MDR1. Gain-of-function (GOF) mutations in Mrr1 are a frequent cause of resistance to the antifungal drug fluconazole, especially during long-term treatment of oropharyngeal candidiasis in AIDS patients, but they may also reduce the fitness of the fungus in the absence of the drug. Fluconazole-resistant clinical C. albicans isolates containing GOF mutations in Mrr1 displayed enhanced Hst 5 resistance, demonstrating that antimycotic therapy can promote the evolution of strains that simultaneously have acquired increased resistance against an innate host defense mechanism and are thereby better adapted to specific host niches.
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Affiliation(s)
- Irene A. I. Hampe
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Justin Friedman
- Department of Oral Biology, University at Buffalo, Buffalo, New York, United States of America
| | - Mira Edgerton
- Department of Oral Biology, University at Buffalo, Buffalo, New York, United States of America
| | - Joachim Morschhäuser
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
- * E-mail:
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McCarthy MW, Kontoyiannis DP, Cornely OA, Perfect JR, Walsh TJ. Novel Agents and Drug Targets to Meet the Challenges of Resistant Fungi. J Infect Dis 2017; 216:S474-S483. [PMID: 28911042 DOI: 10.1093/infdis/jix130] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The emergence of drug-resistant fungi poses a major threat to human health. Despite advances in preventive, diagnostic, and therapeutic interventions, resistant fungal infections continue to cause significant morbidity and mortality in patients with compromised immunity, underscoring the urgent need for new antifungal agents. In this article, we review the challenges associated with identifying broad-spectrum antifungal drugs and highlight novel targets that could enhance the armamentarium of agents available to treat drug-resistant invasive fungal infections.
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Affiliation(s)
- Matthew W McCarthy
- Division of General Internal Medicine, Weill Cornell Medicine, New York, New York
| | | | - Oliver A Cornely
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Department I of Internal Medicine, Clinical Trials Centre Cologne (ZKS Köln), University of Cologne, Germany
| | - John R Perfect
- Division of Infectious Diseases, Duke University, Durham, North Carolina
| | - Thomas J Walsh
- Transplantation-Oncology Infectious Diseases Program, Weill Cornell Medicine, New York, New York
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45
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Benhamou RI, Bibi M, Steinbuch KB, Engel H, Levin M, Roichman Y, Berman J, Fridmana M. Real-Time Imaging of the Azole Class of Antifungal Drugs in Live Candida Cells. ACS Chem Biol 2017; 12:1769-1777. [PMID: 28472585 PMCID: PMC7030953 DOI: 10.1021/acschembio.7b00339] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Azoles are the most commonly used class of antifungal drugs, yet where they localize within fungal cells and how they are imported remain poorly understood. Azole antifungals target lanosterol 14α-demethylase, a cytochrome P450, encoded by ERG11 in Candida albicans, the most prevalent fungal pathogen. We report the synthesis of fluorescent probes that permit visualization of antifungal azoles within live cells. Probe 1 is a dansyl dye-conjugated azole, and probe 2 is a Cy5-conjugated azole. Docking computations indicated that each of the probes can occupy the active site of the target cytochrome P450. Like the azole drug fluconazole, probe 1 is not effective against a mutant that lacks the target cytochrome P450. In contrast, the azole drug ketoconazole and probe 2 retained some antifungal activity against mutants lacking the target cytochrome P450, implying that both act against more than one target. Both fluorescent azole probes colocalized with the mitochondria, as determined by fluorescence microscopy with MitoTracker dye. Thus, these fluorescent probes are useful molecular tools that can lead to detailed information about the activity and localization of the important azole class of antifungal drugs.
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Affiliation(s)
- Raphael I. Benhamou
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Maayan Bibi
- Dept. of Molecular Microbiology & Biotechnology, School of Molecular Cell Biology and Biotechnology, George Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Kfir B. Steinbuch
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Hamutal Engel
- BLAVATNIK CENTER for Drug Discovery, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Maayan Levin
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Yael Roichman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Judith Berman
- Dept. of Molecular Microbiology & Biotechnology, School of Molecular Cell Biology and Biotechnology, George Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Micha Fridmana
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
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46
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The Etest Performed Directly on Blood Culture Bottles Is a Reliable Tool for Detection of Fluconazole-Resistant Candida albicans Isolates. Antimicrob Agents Chemother 2017; 61:AAC.00400-17. [PMID: 28483951 DOI: 10.1128/aac.00400-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/28/2017] [Indexed: 11/20/2022] Open
Abstract
We assessed the ability of the Etest performed directly on positive blood cultures (ETDIR) to detect fluconazole susceptibility in 6 fluconazole-resistant and 12 fluconazole-susceptible Candida albicans isolates, according to CLSI M27-A3 and EUCAST EDef 7.2 procedures. Categorical agreement between ETDIR and broth microdilution was 100% when the trays were incubated at 25°C and trailing effect was ruled out. ETDIR is a reliable procedure when screening for the presence of fluconazole resistance in C. albicans.
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47
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Competitive Fitness of Fluconazole-Resistant Clinical Candida albicans Strains. Antimicrob Agents Chemother 2017; 61:AAC.00584-17. [PMID: 28461316 DOI: 10.1128/aac.00584-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 04/23/2017] [Indexed: 12/27/2022] Open
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 and Tac1, which result in constitutive overexpression of multidrug efflux pumps, and Upc2, which result in constitutive overexpression of ergosterol biosynthesis genes. However, the deregulated gene expression that is caused by hyperactive forms of these transcription factors also reduces the fitness of the cells in the absence of the drug. To investigate whether fluconazole-resistant clinical C. albicans isolates have overcome the fitness costs of drug resistance, we assessed the relative fitness of C. albicans isolates containing resistance mutations in these transcription factors in competition with matched drug-susceptible isolates from the same patients. Most of the fluconazole-resistant isolates were outcompeted by the corresponding drug-susceptible isolates when grown in rich medium without fluconazole. On the other hand, some resistant isolates with gain-of-function mutations in MRR1 did not exhibit reduced fitness under these conditions. In a mouse model of disseminated candidiasis, three out of four tested fluconazole-resistant clinical isolates did not exhibit a significant fitness defect. However, all four fluconazole-resistant isolates were outcompeted by the matched susceptible isolates in a mouse model of gastrointestinal colonization, demonstrating that the effects of drug resistance on in vivo fitness depend on the host niche. Collectively, our results indicate that the fitness costs of drug resistance in C. albicans are not easily remediated, especially when proper control of gene expression is required for successful adaptation to life within a mammalian host.
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48
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Joshua IM, Höfken T. From Lipid Homeostasis to Differentiation: Old and New Functions of the Zinc Cluster Proteins Ecm22, Upc2, Sut1 and Sut2. Int J Mol Sci 2017; 18:ijms18040772. [PMID: 28379181 PMCID: PMC5412356 DOI: 10.3390/ijms18040772] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/27/2017] [Accepted: 03/31/2017] [Indexed: 12/27/2022] Open
Abstract
Zinc cluster proteins are a large family of transcriptional regulators with a wide range of biological functions. The zinc cluster proteins Ecm22, Upc2, Sut1 and Sut2 have initially been identified as regulators of sterol import in the budding yeast Saccharomyces cerevisiae. These proteins also control adaptations to anaerobic growth, sterol biosynthesis as well as filamentation and mating. Orthologs of these zinc cluster proteins have been identified in several species of Candida. Upc2 plays a critical role in antifungal resistance in these important human fungal pathogens. Upc2 is therefore an interesting potential target for novel antifungals. In this review we discuss the functions, mode of actions and regulation of Ecm22, Upc2, Sut1 and Sut2 in budding yeast and Candida.
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Affiliation(s)
| | - Thomas Höfken
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK.
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49
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Khosravi Rad K, Falahati M, Roudbary M, Farahyar S, Nami S. Overexpression of MDR-1 and CDR-2 genes in fluconazole resistance of Candida albicans isolated from patients with vulvovaginal candidiasis. Curr Med Mycol 2016; 2:24-29. [PMID: 28959792 PMCID: PMC5611693 DOI: 10.18869/acadpub.cmm.2.4.24] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Background and Purpose: Candida albicans (C. albicans) is an opportunistic fungus that can colonize women’s mucosal epithelial cell surfaces, causing vulvovaginitis in specific circumstances. The major genes contributing to drug resistance in C. albicans are the candida drug resistance (CDR) and multi drug resistance (MDR) genes. The purpose of this study was to evaluate the CDR-2 and MDR-1 gene expression patterns in C. albicans strains isolated from patients with recurrent vulvovaginal candidiasis. Materials and Methods: In this study, 40 isolates of fluconazole-resistant C. albicans were cultured on Sabouraud dextrose agar. These isolates were collected from women with vulvovaginitis who were referred to a clinic in Tehran, Iran, and transferred to a mycology laboratory. Then, RNA was extracted from the isolates using phenol-chloroform and glass beads, and the complementary DNA (cDNA) was synthetized. To detect the semi-quantitative expression of CDR-2 and MDR-1 genes, the reverse transcriptase-PCR (RT-PCR) technique was performed using specific primers. Results: Our findings indicated that of the 40 C. albicans isolates, 35 (87.5%) strains were positive for mRNA of the CDR-2 gene, 32 (80%) strains expressed mRNA of the MDR-1 gene, and 30 (75%) strains were confirmed to express mRNA of both the CDR-2 and MDR-1 genes simultaneously using the RT-PCR assay. Conclusion: According to the obtained results, the expression rates of CDR-2 and MDR-1 genes were high in fluconazole-resistant C. albicans isolates, which can cause treatments to fail and result in chronic infections. Inhibiting these important genes using novel or natural agents can help with the treatment of chronic and recurrent vaginitis.
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Affiliation(s)
- K Khosravi Rad
- Department of Medical Mycology and Parasitology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - M Falahati
- Department of Medical Mycology and Parasitology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - M Roudbary
- Department of Medical Mycology and Parasitology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - S Farahyar
- Department of Medical Mycology and Parasitology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - S Nami
- Departement of Medical Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical sciences, Tabriz, Iran
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50
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K Redhu A, Shah AH, Prasad R. MFS transporters of Candida species and their role in clinical drug resistance. FEMS Yeast Res 2016; 16:fow043. [PMID: 27188885 DOI: 10.1093/femsyr/fow043] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2016] [Indexed: 12/14/2022] Open
Abstract
ABC (ATP-binding cassette) and MFS (major facilitator superfamily) exporters, belonging to two different superfamilies, are one of the most prominent contributors of multidrug resistance (MDR) in yeast. While the role of ABC efflux pump proteins in the development of MDR is well documented, the MFS transporters which are also implicated in clinical drug resistance have not received due attention. The MFS superfamily is the largest known family of secondary active membrane carriers, and MFS exporters are capable of transporting a host of substrates ranging from small molecules, including organic and inorganic ions, to complex biomolecules, such as peptide and lipid moieties. A few of the members of the drug/H(+) antiporter family of the MFS superfamily function as multidrug transporters and employ downhill transport of protons to efflux their respective substrates. This review focuses on the recent developments in MFS of Candida and highlights their role in drug transport by using the example of the relatively well characterized promiscuous Mdr1 efflux pump of the pathogenic yeast C. albicans.
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Affiliation(s)
- Archana K Redhu
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Abdul H Shah
- Department of Bioresources, University of Kashmir, Srinagar 190006, India
| | - Rajendra Prasad
- Institute of Integrative Sciences and Health and Institute of Biotechnology, Amity University Haryana, Amity Education Valley, Gurgaon 122413, India
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