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Cárdenas Parra LY, Rojas Rodríguez AE, Pérez Cárdenas JE, Pérez-Agudelo JM. Molecular Evaluation of the mRNA Expression of the ERG11, ERG3, CgCDR1, and CgSNQ2 Genes Linked to Fluconazole Resistance in Candida glabrata in a Colombian Population. J Fungi (Basel) 2024; 10:509. [PMID: 39057394 PMCID: PMC11277825 DOI: 10.3390/jof10070509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/12/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
INTRODUCTION The study of Candida glabrata genes associated with fluconazole resistance, from a molecular perspective, increases the understanding of the phenomenon with a view to its clinical applicability. OBJECTIVE We sought to establish the predictive molecular profile of fluconazole resistance in Candida glabrata by analyzing the ERG11, ERG3, CgCDR1, and CgSNQ2 genes. METHOD Expression was quantified using RT-qPCR. Metrics were obtained through molecular docking and Fisher discriminant functions. Additionally, a predictive classification was made against the susceptibility of C. glabrata to fluconazole. RESULTS The relative expression of the ERG3, CgCDR1, and CgSNQ2 genes was higher in the fluconazole-resistant strains than in the fluconazole-susceptible, dose-dependent strains. The gene with the highest relative expression in the fluconazole-exposed strains was CgCDR1, and in both the resistant and susceptible, dose-dependent strains exposed to fluconazole, this was also the case. The molecular docking model generated a median number of contacts between fluconazole and ERG11 that was lower than the median number of contacts between fluconazole and ERG3, -CgCDR1, and -CgSNQ2. The predicted classification through the multivariate model for fluconazole susceptibility achieved an accuracy of 73.5%. CONCLUSION The resistant strains had significant expression levels of genes encoding efflux pumps and the ERG3 gene. Molecular analysis makes the identification of a low affinity between fluconazole and its pharmacological target possible, which may explain the lower intrinsic susceptibility of the fungus to fluconazole.
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Affiliation(s)
- Leidy Yurany Cárdenas Parra
- Facultad de Ciencias para la Salud, Universidad de Caldas, Manizales 170004, Colombia; (L.Y.C.P.); (J.E.P.C.); (J.M.P.-A.)
- Facultad de Ciencias de la Salud, Universidad Católica de Manizales, Manizales 170001, Colombia
| | | | - Jorge Enrique Pérez Cárdenas
- Facultad de Ciencias para la Salud, Universidad de Caldas, Manizales 170004, Colombia; (L.Y.C.P.); (J.E.P.C.); (J.M.P.-A.)
| | - Juan Manuel Pérez-Agudelo
- Facultad de Ciencias para la Salud, Universidad de Caldas, Manizales 170004, Colombia; (L.Y.C.P.); (J.E.P.C.); (J.M.P.-A.)
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Dunaiski CM, Kock MM, Chan WY, Ismail A, Peters RPH. Molecular epidemiology and antimicrobial resistance of vaginal Candida glabrata isolates in Namibia. Med Mycol 2024; 62:myae009. [PMID: 38308518 DOI: 10.1093/mmy/myae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/16/2023] [Accepted: 02/01/2024] [Indexed: 02/04/2024] Open
Abstract
Candida glabrata is the most common non-albicans Candida species that causes vulvovaginal candidiasis (VVC). Given the intrinsically low susceptibility of C. glabrata to azole drugs, investigations into C. glabrata prevalence, fungal susceptibility profile, and molecular epidemiology are necessary to optimise the treatment of VVC. This molecular epidemiological study was conducted to determine antifungal drug profile, single nucleotide polymorphisms (SNPs) associated with phenotypic antifungal resistance and epidemic diversity of C. glabrata isolates from women with VVC in Namibia. Candida glabrata isolates were identified using phenotypic and molecular methods. Antifungal susceptibility of strains was determined for fluconazole, itraconazole, amphotericin B, and anidulafungin. Whole genome sequencing was used to determine SNPs in antifungal resistance genes and sequence type (ST) allocation. Among C. glabrata isolates, all (20/20; 100%) exhibited phenotypic resistance to the azole class antifungal drug, (fluconazole), and phenotypic susceptibility to the polyene class (amphotericin B), and the echinocandins (anidulafungin). Non-synonymous SNPs were identified in antifungal resistance genes of all fluconazole-resistant C. glabrata isolates including ERG6 (15%), ERG7 (15%), CgCDR1 (25%), CgPDR1 (60%), SNQ2 (10%), FKS1 (5.0%), FKS2 (5.0%), CgFPS1 (5.0%), and MSH2 (15%). ST15 (n = 8/20, 40%) was predominant. This study provides important insight into phenotypic and genotypic antifungal resistance across C. glabrata isolates from women with VVC in Namibia. In this study, azole resistance is determined by an extensive range of SNPs, while the observed polyene and echinocandin resistance-associated SNPs despite phenotypic susceptibility require further investigation.
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Affiliation(s)
- Cara M Dunaiski
- Namibia University of Sciences and Technology, Department of Health and Applied Sciences, Windhoek 10005, Namibia
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
| | - Marleen M Kock
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
- National Health Laboratory Service, Tshwane, Academic Division, Pretoria 3191, South Africa
| | - Wai Yin Chan
- Sequencing Core Facility, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg 2131, South Africa
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0081, South Africa
- Right to care, Centurion 0157, South Africa
| | - Arshad Ismail
- Sequencing Core Facility, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg 2131, South Africa
- Department of Biochemistry and Microbiology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou 0950, South Africa
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa
| | - Remco P H Peters
- University of Pretoria, Department of Medical Microbiology, Pretoria 0001, South Africa
- University of Cape Town, Division of Medical Microbiology, Cape Town 7701, South Africa
- Foundation for Professional Development, Research Unit, East London 5217, South Africa
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Zeeshan M, Memon S, Malick A, Naqvi SF, Farooqi J, Ghanchi NK, Jabeen K. Fluconazole-resistant Candida parapsilosis complex candidemia and analysis of mutations in the ERG11 gene from Pakistan. Mycoses 2024; 67:e13677. [PMID: 37990393 DOI: 10.1111/myc.13677] [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: 07/24/2023] [Revised: 11/10/2023] [Accepted: 11/11/2023] [Indexed: 11/23/2023]
Abstract
BACKGROUND Recent reports of the emergence of fluconazole resistance in Candida parapsilosis species complex poses a challenge, more specifically in settings where echinocandin-based treatment regime is not feasible. OBJECTIVE This study reported emergence of fluconazole resistance in C. parapsilosis species complex strains isolated from blood cultures. MATERIALS AND METHODS This retrospective observational study was conducted from 2018 to 2020 at a tertiary care laboratory from Pakistan. Fluconazole-resistant C. parapsilosis species complex fungemia cases were identified from laboratory database and clinical details were collected. Identification of C. parapsilosis species complex was done using API 20C AUX and Cornmeal Tween80 agar morphology. Minimum inhibitory concentrations (MICs) were determined using Sensititre YeastONE and interpretation was done with CLSI M60 ED1:2017. ERG11 gene region was amplified and sequenced by Sanger sequencing and analysed by MEGA 11 Software. RESULTS A total of 13 (8.5%) fluconazole-resistant isolates were identified from 152 C. parapsilosis species complex candidemia cases. Fluconazole MICs of resistant isolates ranged between 8 and 256 μg/mL. Analysis of ERG11 gene revealed nonsynonymous mutations at position Y132F in 86% of the fluconazole-resistant isolates. Diabetes and hospitalization were important risk factors for candidemia with fluconazole-resistant C. parapsilosis complex. CONCLUSION This is the first report of the emergence and molecular mechanisms of fluconazole resistance in C. parapsilosis species complex from Pakistan. Y132F mutation in the ERG11 gene was the most common mutation in fluconazole-resistant strains. These findings are concerning and necessitate better diagnostics, newer antifungals, ongoing surveillance and further insights on resistance mechanisms in the country.
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Affiliation(s)
- Mohammad Zeeshan
- Department of Pathology & Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Saba Memon
- Department of Pathology & Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Ayesha Malick
- Aga Khan University Medical College, Karachi, Pakistan
| | - Syed Faheem Naqvi
- Department of Pathology & Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Joveria Farooqi
- Department of Pathology & Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Najia Karim Ghanchi
- Department of Pathology & Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Kauser Jabeen
- Department of Pathology & Laboratory Medicine, Aga Khan University, Karachi, Pakistan
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Czajka KM, Venkataraman K, Brabant-Kirwan D, Santi SA, Verschoor C, Appanna VD, Singh R, Saunders DP, Tharmalingam S. Molecular Mechanisms Associated with Antifungal Resistance in Pathogenic Candida Species. Cells 2023; 12:2655. [PMID: 37998390 PMCID: PMC10670235 DOI: 10.3390/cells12222655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023] Open
Abstract
Candidiasis is a highly pervasive infection posing major health risks, especially for immunocompromised populations. Pathogenic Candida species have evolved intrinsic and acquired resistance to a variety of antifungal medications. The primary goal of this literature review is to summarize the molecular mechanisms associated with antifungal resistance in Candida species. Resistance can be conferred via gain-of-function mutations in target pathway genes or their transcriptional regulators. Therefore, an overview of the known gene mutations is presented for the following antifungals: azoles (fluconazole, voriconazole, posaconazole and itraconazole), echinocandins (caspofungin, anidulafungin and micafungin), polyenes (amphotericin B and nystatin) and 5-fluorocytosine (5-FC). The following mutation hot spots were identified: (1) ergosterol biosynthesis pathway mutations (ERG11 and UPC2), resulting in azole resistance; (2) overexpression of the efflux pumps, promoting azole resistance (transcription factor genes: tac1 and mrr1; transporter genes: CDR1, CDR2, MDR1, PDR16 and SNQ2); (3) cell wall biosynthesis mutations (FKS1, FKS2 and PDR1), conferring resistance to echinocandins; (4) mutations of nucleic acid synthesis/repair genes (FCY1, FCY2 and FUR1), resulting in 5-FC resistance; and (5) biofilm production, promoting general antifungal resistance. This review also provides a summary of standardized inhibitory breakpoints obtained from international guidelines for prominent Candida species. Notably, N. glabrata, P. kudriavzevii and C. auris demonstrate fluconazole resistance.
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Affiliation(s)
- Karolina M. Czajka
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
| | - Krishnan Venkataraman
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | | | - Stacey A. Santi
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Chris Verschoor
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Vasu D. Appanna
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | - Ravi Singh
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Deborah P. Saunders
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Sujeenthar Tharmalingam
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
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Tsybruk TV, Kaluzhskiy LA, Mezentsev YV, Makarieva TN, Tabakmaher KM, Ivanchina NV, Dmitrenok PS, Baranovsky AV, Gilep AA, Ivanov AS. Molecular Cloning, Heterologous Expression, Purification, and Evaluation of Protein-Ligand Interactions of CYP51 of Candida krusei Azole-Resistant Fungal Strain. Biomedicines 2023; 11:2873. [PMID: 38001874 PMCID: PMC10668980 DOI: 10.3390/biomedicines11112873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/17/2023] [Accepted: 10/19/2023] [Indexed: 11/26/2023] Open
Abstract
Due to the increasing prevalence of fungal diseases caused by fungi of the genus Candida and the development of pathogen resistance to available drugs, the need to find new effective antifungal agents has increased. Azole antifungals, which are inhibitors of sterol-14α-demethylase or CYP51, have been widely used in the treatment of fungal infections over the past two decades. Of special interest is the study of C. krusei CYP51, since this fungus exhibit resistance not only to azoles, but also to other antifungal drugs and there is no available information about the ligand-binding properties of CYP51 of this pathogen. We expressed recombinant C. krusei CYP51 in E. coli cells and obtained a highly purified protein. Application of the method of spectrophotometric titration allowed us to study the interaction of C. krusei CYP51 with various ligands. In the present work, the interaction of C. krusei CYP51 with azole inhibitors, and natural and synthesized steroid derivatives was evaluated. The obtained data indicate that the resistance of C. krusei to azoles is not due to the structural features of CYP51 of this microorganism, but rather to another mechanism. Promising ligands that demonstrated sufficiently strong binding in the micromolar range to C. krusei CYP51 were identified, including compounds 99 (Kd = 1.02 ± 0.14 µM) and Ch-4 (Kd = 6.95 ± 0.80 µM). The revealed structural features of the interaction of ligands with the active site of C. krusei CYP51 can be taken into account in the further development of new selective modulators of the activity of this enzyme.
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Affiliation(s)
- Tatsiana V. Tsybruk
- Institute of Bioorganic Chemistry NASB, 5 Building 2, V.F. Kuprevich Street, 220084 Minsk, Belarus; (A.V.B.); (A.A.G.)
| | - Leonid A. Kaluzhskiy
- Institute of Biomedical Chemistry, Pogodinskaya Str. 10 Building 8, 119121 Moscow, Russia; (L.A.K.); (Y.V.M.)
| | - Yuri V. Mezentsev
- Institute of Biomedical Chemistry, Pogodinskaya Str. 10 Building 8, 119121 Moscow, Russia; (L.A.K.); (Y.V.M.)
| | - Tatyana N. Makarieva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Pr. 100-let Vladivostoku 159, 690022 Vladivostok, Russia; (T.N.M.); (K.M.T.); (N.V.I.); (P.S.D.)
| | - Kseniya M. Tabakmaher
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Pr. 100-let Vladivostoku 159, 690022 Vladivostok, Russia; (T.N.M.); (K.M.T.); (N.V.I.); (P.S.D.)
| | - Natalia V. Ivanchina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Pr. 100-let Vladivostoku 159, 690022 Vladivostok, Russia; (T.N.M.); (K.M.T.); (N.V.I.); (P.S.D.)
| | - Pavel S. Dmitrenok
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Pr. 100-let Vladivostoku 159, 690022 Vladivostok, Russia; (T.N.M.); (K.M.T.); (N.V.I.); (P.S.D.)
| | - Alexander V. Baranovsky
- Institute of Bioorganic Chemistry NASB, 5 Building 2, V.F. Kuprevich Street, 220084 Minsk, Belarus; (A.V.B.); (A.A.G.)
| | - Andrei A. Gilep
- Institute of Bioorganic Chemistry NASB, 5 Building 2, V.F. Kuprevich Street, 220084 Minsk, Belarus; (A.V.B.); (A.A.G.)
- Institute of Biomedical Chemistry, Pogodinskaya Str. 10 Building 8, 119121 Moscow, Russia; (L.A.K.); (Y.V.M.)
| | - Alexis S. Ivanov
- Institute of Biomedical Chemistry, Pogodinskaya Str. 10 Building 8, 119121 Moscow, Russia; (L.A.K.); (Y.V.M.)
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Hatami F, Manifar S, Asghari-Paskiabi F, Bagheri Amiri F, Nojoumi SA, Jahanshiri Z. Molecular mechanisms of azole resistance in Candida glabrata isolated from oropharyngeal candidiasis in head and neck cancer patients. Arch Oral Biol 2023; 154:105757. [PMID: 37419061 DOI: 10.1016/j.archoralbio.2023.105757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 06/24/2023] [Accepted: 06/29/2023] [Indexed: 07/09/2023]
Abstract
OBJECTIVE The aim of the current work was to assess the molecular mechanisms of fluconazole-resistant Candida glabrata strains isolated from oropharyngeal candidiasis (OPC) in head and neck patients, as well as evaluation of virulence factors. DESIGN Antifungal susceptibility pattern of sixty six clinical isolates of C. glabrata were evaluated by broth-microdilution method. The expression of ERG11, CDR1, CDR2, PDR1 genes as well as ERG11 gene capable of possible mutations was also detected in 21 fluconazol-resistant C. glabrata isolates. Phospholipase and proteinase activity of these isolates was estimated, too. The correlation between the virulence factors, antifungal susceptibility patterns and cancer type was also analyzed. RESULTS Seven synonymous and four non-synonymous mutations were found in 21 fluconazole-resistant C. glabrata isolates; subsequently, four amino acid substitutions including H257P, Q47H, S487Y and I285N were then reported for the first time. High expression of CDR1 and PDR1 in related to other gene findings were tested in these isolates. Additionally, there was no significant difference between stage of cancer and MIC of all antimicrobial drugs. Significant differences between MIC of fluconazole, voriconazole and cancer types were also, found. The proteinase activity (92.4%) was higher than phospholipase activity in the isolates. Further, no significant difference between proteinase (rs: 0.003), phospholipase (rs: -0.107) activity and fluconazole MICs was observed. CONCLUSION C. glabrata isolated from OPC in head and neck patients represented high capacities for proteolytic enzymes activity and high mRNA level of CDR1 and PDR1 gene and ERG11 mutations play an important role in azole drug resistance.
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Affiliation(s)
- Farahnaz Hatami
- Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Soheila Manifar
- Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, Cancer Institute of Tehran, Imam Khomeini Hospital Complex, Tehran, Iran
| | | | - Fahimeh Bagheri Amiri
- Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Ali Nojoumi
- Department of Mycobacteriology and Pulmonary research, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Zahra Jahanshiri
- Department of Mycology, Pasteur Institute of Iran, Tehran, Iran.
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Franconi I, Rizzato C, Poma N, Tavanti A, Lupetti A. Candida parapsilosis sensu stricto Antifungal Resistance Mechanisms and Associated Epidemiology. J Fungi (Basel) 2023; 9:798. [PMID: 37623569 PMCID: PMC10456088 DOI: 10.3390/jof9080798] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/18/2023] [Accepted: 07/25/2023] [Indexed: 08/26/2023] Open
Abstract
Fungal diseases cause millions of deaths per year worldwide. Antifungal resistance has become a matter of great concern in public health. In recent years rates of non-albicans species have risen dramatically. Candida parapsilosis is now reported to be the second most frequent species causing candidemia in several countries in Europe, Latin America, South Africa and Asia. Rates of acquired azole resistance are reaching a worrisome threshold from multiple reports as in vitro susceptibility testing is now starting also to explore tolerance and heteroresistance to antifungal compounds. With this review, the authors seek to evaluate known antifungal resistance mechanisms and their worldwide distribution in Candida species infections with a specific focus on C. parapsilosis.
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Affiliation(s)
- Iacopo Franconi
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Via San Zeno, 37, 56127 Pisa, Italy; (I.F.); (C.R.)
| | - Cosmeri Rizzato
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Via San Zeno, 37, 56127 Pisa, Italy; (I.F.); (C.R.)
| | - Noemi Poma
- Department of Biology, University of Pisa, Via San Zeno, 37, 56127 Pisa, Italy; (N.P.); (A.T.)
| | - Arianna Tavanti
- Department of Biology, University of Pisa, Via San Zeno, 37, 56127 Pisa, Italy; (N.P.); (A.T.)
| | - Antonella Lupetti
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Via San Zeno, 37, 56127 Pisa, Italy; (I.F.); (C.R.)
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Sathi FA, Paul SK, Ahmed S, Alam MM, Nasreen SA, Haque N, Islam A, Nila SS, Afrin SZ, Aung MS, Kobayashi N. Prevalence and Antifungal Susceptibility of Clinically Relevant Candida Species, Identification of Candida auris and Kodamaea ohmeri in Bangladesh. Trop Med Infect Dis 2022; 7:tropicalmed7090211. [PMID: 36136623 PMCID: PMC9506023 DOI: 10.3390/tropicalmed7090211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
Candida species are major fungal pathogens in humans. The aim of this study was to determine the prevalence of individual Candida species and their susceptibility to antifungal drugs among clinical isolates in a tertiary care hospital in Bangladesh. During a 10-month period in 2021, high vaginal swabs (HVSs), blood, and aural swabs were collected from 360 patients. From these specimens, Candida spp. was isolated from cultures on Sabouraud dextrose agar media, and phenotypic and genetic analyses were performed. A total of 109 isolates were recovered, and C. albicans accounted for 37%, being derived mostly from HVSs. Among non-albicans Candida (NAC), C. parapsilosis was the most frequent, followed by C. ciferrii, C. tropicalis, and C. glabrata. Three isolates from blood and two isolates from aural discharge were genetically identified as C. auris and Kodamaea ohmeri, respectively. NAC isolates were more resistant to fluconazole (overall rate, 29%) than C. albicans (10%). Candida isolates from blood showed 95% susceptibility to voriconazole and less susceptibility to fluconazole (67%). Two or three amino acid substitutions were detected in the ERG11 of two fluconazole-resistant C. albicans isolates. The present study is the first to reveal the prevalence of Candida species and their antifungal susceptibility in Bangladesh.
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Affiliation(s)
- Fardousi Akter Sathi
- Department of Microbiology, Mymensingh Medical College, Mymensingh 2200, Bangladesh
| | | | - Salma Ahmed
- Department of Microbiology, Mugda Medical College, Dhaka 1214, Bangladesh
| | | | | | - Nazia Haque
- Department of Microbiology, Mymensingh Medical College, Mymensingh 2200, Bangladesh
| | - Arup Islam
- Department of Microbiology, Mymensingh Medical College, Mymensingh 2200, Bangladesh
| | - Sultana Shabnam Nila
- Department of Microbiology, Mymensingh Medical College, Mymensingh 2200, Bangladesh
| | - Sultana Zahura Afrin
- Department of Microbiology, Mymensingh Medical College, Mymensingh 2200, Bangladesh
| | - Meiji Soe Aung
- Department of Hygiene, School of Medicine, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Nobumichi Kobayashi
- Department of Hygiene, School of Medicine, Sapporo Medical University, Sapporo 060-8556, Japan
- Correspondence: ; Tel.: +81-11-611-2111
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Handelman M, Osherov N. Experimental and in-host evolution of triazole resistance in human pathogenic fungi. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:957577. [PMID: 37746192 PMCID: PMC10512370 DOI: 10.3389/ffunb.2022.957577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/19/2022] [Indexed: 09/26/2023]
Abstract
The leading fungal pathogens causing systemic infections in humans are Candida spp., Aspergillus fumigatus, and Cryptococcus neoformans. The major class of antifungals used to treat such infections are the triazoles, which target the cytochrome P450 lanosterol 14-α-demethylase, encoded by the ERG11 (yeasts)/cyp51A (molds) genes, catalyzing a key step in the ergosterol biosynthetic pathway. Triazole resistance in clinical fungi is a rising concern worldwide, causing increasing mortality in immunocompromised patients. This review describes the use of serial clinical isolates and in-vitro evolution toward understanding the mechanisms of triazole resistance. We outline, compare, and discuss how these approaches have helped identify the evolutionary pathways taken by pathogenic fungi to acquire triazole resistance. While they all share a core mechanism (mutation and overexpression of ERG11/cyp51A and efflux transporters), their timing and mechanism differs: Candida and Cryptococcus spp. exhibit resistance-conferring aneuploidies and copy number variants not seen in A. fumigatus. Candida spp. have a proclivity to develop resistance by undergoing mutations in transcription factors (TAC1, MRR1, PDR5) that increase the expression of efflux transporters. A. fumigatus is especially prone to accumulate resistance mutations in cyp51A early during the evolution of resistance. Recently, examination of serial clinical isolates and experimental lab-evolved triazole-resistant strains using modern omics and gene editing tools has begun to realize the full potential of these approaches. As a result, triazole-resistance mechanisms can now be analyzed at increasingly finer resolutions. This newfound knowledge will be instrumental in formulating new molecular approaches to fight the rapidly emerging epidemic of antifungal resistant fungi.
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Affiliation(s)
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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10
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Atim PB, Meya DB, Gerlach ES, Muhanguzi D, Male A, Kanamwanji B, Nielsen K. Lack of Association between Fluconazole Susceptibility and ERG11 Nucleotide Polymorphisms in Cryptococcus neoformans Clinical Isolates from Uganda. J Fungi (Basel) 2022; 8:508. [PMID: 35628763 PMCID: PMC9145384 DOI: 10.3390/jof8050508] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/04/2022] [Accepted: 05/10/2022] [Indexed: 11/22/2022] Open
Abstract
Fluconazole is the drug of choice for cryptococcal meningitis (CM) monoprophylaxis in resource-limited settings such as Uganda. Emerging fluconazole resistance linked to mutations in the Cryptococcus neoformansERG11 gene (CYP51) has been observed in clinical isolates. Currently, the single nucleotide polymorphisms [SNPs] in the Cryptococcus spp. ERG11 gene that could be responsible for fluconazole resistance are poorly characterized within Ugandan C. neoformans clinical isolates. If available, this information would be useful in the management of cryptococcosis among HIV patients. This cross-sectional study investigates the SNPs present in the coding region of the C. neoformansERG11 gene to determine the relationship between the SNPs identified and fluconazole susceptibility of the clinical isolates. 310 C. neoformans isolates recovered from the Cerebrospinal Fluid (CSF) of patients with HIV and cryptococcal meningitis were examined. The fluconazole half-maximal inhibitory concentrations (IC50 range: 0.25−32 μg/mL) was determined using the microbroth dilution method. A total of 56.1% of the isolates had low IC50 values of <8 μg/mL while 43.9% had high IC50 values ≥ 8 μg/mL. We amplified and sequenced 600 bp of the ERG11 coding sequence from 40 of the clinical isolates. Novel synonymous and 2 missense mutations, S460T and A457V, were identified in the ERG11 gene. The identified SNPs were not associated with differences in fluconazole IC50 values in vitro (p = 0.179).
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Affiliation(s)
| | - David B. Meya
- Infectious Diseases Institute, Kampala P.O. Box 22418, Uganda;
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455, USA; (E.S.G.); (K.N.)
| | - Elliot S. Gerlach
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455, USA; (E.S.G.); (K.N.)
| | - Dennis Muhanguzi
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala P.O. Box 7062, Uganda;
| | - Allan Male
- International Centre for Tropical Agriculture (CIAT)—Uganda, Kampala P.O. Box 6247, Uganda;
| | - Benedict Kanamwanji
- National Microbiology Reference Laboratory (NMRL), Kampala P.O. Box 7272, Uganda;
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455, USA; (E.S.G.); (K.N.)
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11
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Bohner F, Papp C, Gácser A. The effect of antifungal resistance development on the virulence of Candida species. FEMS Yeast Res 2022; 22:6552956. [PMID: 35325128 PMCID: PMC9466593 DOI: 10.1093/femsyr/foac019] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/24/2022] [Accepted: 03/21/2022] [Indexed: 11/12/2022] Open
Abstract
In recent years, the relevance of diseases associated with fungal pathogens increased worldwide. Members of the Candida genus are responsible for the greatest number of fungal bloodstream infections every year. Epidemiological data consistently indicate a modest shift toward non-albicans species, albeit Candidaalbicans is still the most recognizable species within the genus. As a result, the number of clinically relevant pathogens has increased, and, despite their distinct pathogenicity features, the applicable antifungal agents remained the same. For bloodstream infections, only three classes of drugs are routinely used, namely polyenes, azoles and echinocandins. Antifungal resistance toward all three antifungal drug classes frequently occurs in clinical settings. Compared with the broad range of literature on virulence and antifungal resistance of Candida species separately, only a small portion of studies examined the effect of resistance on virulence. These studies found that resistance to polyenes and echinocandins concluded in significant decrease in the virulence in different Candida species. Meanwhile, in some cases, resistance to azole type antifungals resulted in increased virulence depending on the species and isolates. These findings underline the importance of studies aiming to dissect the connections of virulence and resistance in Candida species.
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Affiliation(s)
- Flora Bohner
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Csaba Papp
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Attila Gácser
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.,MTA-SZTE "Lendület" Mycobiome Research Group, University of Szeged, Szeged, Hungary
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12
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Huët MAL, Muzahid NH, Lee CZ, Goh CBS, Dwiyanto J, Rahman S, Tan JBL. Molecular typing of multi-drug resistant Candida albicans isolated from the Segamat community, Malaysia. Braz J Microbiol 2021; 52:2351-2356. [PMID: 34235705 DOI: 10.1007/s42770-021-00558-4] [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: 01/06/2021] [Accepted: 06/28/2021] [Indexed: 10/20/2022] Open
Abstract
In the past decade, researchers have focused on the emergence of drug resistance in fungal pathogens such as Candida albicans, also considered as pathobionts that occur harmlessly in the human body but could potentially be triggered to cause diseases. The increasing rate of antifungal resistance in commensal gut fungi is alarming and should be further investigated. Here, we report seven novel MLST (Multi Locus Sequence Typing) genotypes of multi-drug resistant C. albicans isolates obtained from participants of a community study in Segamat, a district in the state of Johor, Malaysia. A total of eight C. albicans were isolated from four individuals, which were found to express high resistance against fluconazole, itraconazole, voriconazole and 5-fluorocytosine antifungals. MLST was performed to assess the clonal relatedness of these drug resistant isolates among themselves and against other strains isolated from other geographical regions. The novel MLST C. albicans sequence types suggest significant genetic changes compared to previous genotypes.
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Affiliation(s)
- Marie Andrea Laetitia Huët
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
| | - Nazmul Hasan Muzahid
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
| | - Chuen Zhang Lee
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
| | - Calvin Bok Sun Goh
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
| | - Jacky Dwiyanto
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
| | - Sadequr Rahman
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia.,Tropical Medicine & Biology Multidisciplinary Platform, Monash University Malaysia, Subang Jaya, Malaysia
| | - Joash Ban Lee Tan
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia.
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13
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Lotfali E, Fattahi A, Sayyahfar S, Ghasemi R, Rabiei MM, Fathi M, Vakili K, Deravi N, Soheili A, Toreyhi H, Shirvani F. A Review on Molecular Mechanisms of Antifungal Resistance in Candida glabrata: Update and Recent Advances. Microb Drug Resist 2021; 27:1371-1388. [PMID: 33956513 DOI: 10.1089/mdr.2020.0235] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Candida glabrata is the second frequent etiologic agent of mucosal and invasive candidiasis. Based on the recent developments in molecular methods, C. glabrata has been introduced as a complex composed of C. glabrata, Candida nivariensis, and Candida bracarensis. The four main classes of antifungal drugs effective against C. glabrata are pyrimidine analogs (flucytosine), azoles, echinocandins, and polyenes. Although the use of antifungal drugs is related to the predictable development of drug resistance, it is not clear why C. glabrata is able to rapidly resist against multiple antifungals in clinics. The enhanced incidence and antifungal resistance of C. glabrata and the high mortality and morbidity need more investigation regarding the resistance mechanisms and virulence associated with C. glabrata; additional progress concerning the drug resistance of C. glabrata has to be further prevented. The present review highlights the mechanism of resistance to antifungal drugs in C. glabrata.
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Affiliation(s)
- Ensieh Lotfali
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Azam Fattahi
- Center for Research and Training in Skin Diseases and Leprosy, Tehran University of Medical Sciences, Tehran, Iran
| | - Shirin Sayyahfar
- Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Ghasemi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Mahdi Rabiei
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mobina Fathi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kimia Vakili
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Niloofar Deravi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amirali Soheili
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Toreyhi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fariba Shirvani
- Pediatric Infections Research Center, Research Institute for Children Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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14
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Advances in Fusarium drug resistance research. J Glob Antimicrob Resist 2021; 24:215-219. [PMID: 33460843 DOI: 10.1016/j.jgar.2020.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/19/2020] [Accepted: 12/16/2020] [Indexed: 12/12/2022] Open
Abstract
Fusarium species cause many diseases in plants and humans, which results in a great number of economic losses every year. The management of plant diseases and related human diseases caused by Fusarium is challenging as many kinds of Fusarium may be intrinsically resistant to antifungal drugs, not to mention the fact that they can acquire drug resistance, which is common in clinical practice. To date, the drug resistance of Fusarium is mainly related to target alterations, drug efflux and biofilm formation. This article reviews recent studies related to the mechanism of Fusarium resistance, and summarizes the key molecules affecting resistance.
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15
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Rodrigues LS, Gazara RK, Passarelli-Araujo H, Valengo AE, Pontes PVM, Nunes-da-Fonseca R, de Souza RF, Venancio TM, Dalla-Costa LM. First Genome Sequences of Two Multidrug-Resistant Candida haemulonii var. vulnera Isolates From Pediatric Patients With Candidemia. Front Microbiol 2020; 11:1535. [PMID: 32719671 PMCID: PMC7350289 DOI: 10.3389/fmicb.2020.01535] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/12/2020] [Indexed: 12/20/2022] Open
Abstract
Candida haemulonii is a complex formed by C. haemulonii sensu stricto, C. haemulonii var. vulnera, and C. duobushaemulonii. Members of this complex are opportunistic pathogens closely related to C. pseudohaemulonii, C. lusitaniae, and C. auris, all members of a multidrug-resistant clade. Complete genome sequences for all members of this group are available in the GenBank database, except for C. haemulonii var. vulnera. Here, we report the first draft genomes of two C. haemulonii var. vulnera (isolates K1 and K2) and comparative genome analysis of closely related fungal species. The isolates were biofilm producers and non-susceptible to amphotericin B and fluconazole. The draft genomes comprised 350 and 387 contigs and total genome sizes of 13.21 and 13.26 Mb, with 5,479 and 5,507 protein-coding genes, respectively, allowing the identification of virulence and resistance genes. Comparative analyses of orthologous genes within the multidrug-resistant clade showed a total of 4,015 core clusters, supporting the conservation of 24,654 proteins and 3,849 single-copy gene clusters. Candida haemulonii var. vulnera shared a larger number of clusters with C. haemulonii and C. auris; however, more singletons were identified in C. lusitaniae and C. auris. Additionally, a multiple sequence alignment of Erg11p proteins revealed variants likely involved in reduced susceptibility to azole and polyene antifungal agents. The data presented in this work will, therefore, be of utmost importance for researchers studying the biology of the C. haemulonii complex and related species.
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Affiliation(s)
- Luiza Souza Rodrigues
- Faculdades Pequeno Príncipe, Curitiba, Brazil.,Instituto de Pesquisas Pelé Pequeno Príncipe, Curitiba, Brazil
| | - Rajesh Kumar Gazara
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil.,Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India.,Department of Electrical Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Hemanoel Passarelli-Araujo
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil.,Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Paula Veronesi Marinho Pontes
- Instituto de Biodiversidade e Sustentabilidade, Núcleo em Ecologia e Desenvolvimento Sócio-Ambiental de Macaé, Universidade Federal do Rio de Janeiro, Macaé, Brazil
| | - Rodrigo Nunes-da-Fonseca
- Instituto de Biodiversidade e Sustentabilidade, Núcleo em Ecologia e Desenvolvimento Sócio-Ambiental de Macaé, Universidade Federal do Rio de Janeiro, Macaé, Brazil
| | - Robson Francisco de Souza
- Laboratório de Estrutura e Evolução de Proteínas, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Thiago Motta Venancio
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil
| | - Libera Maria Dalla-Costa
- Faculdades Pequeno Príncipe, Curitiba, Brazil.,Instituto de Pesquisas Pelé Pequeno Príncipe, Curitiba, Brazil
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16
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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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Cárdenas Parra LY, Perez Cárdenas JE. Mecanismos de resistencia a fluconazol expresados por Candida glabrata: una situación para considerar en la terapéutica. INVESTIGACIÓN EN ENFERMERÍA: IMAGEN Y DESARROLLO 2020. [DOI: 10.11144/javeriana.ie22.mrfe] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Introducción: Los esfuerzos terapéuticos orientados a atender las micosis por Candida spp. se han enfocado en el empleo de azoles; sin embargo, en la literatura científica se discute su beneficio, por los amplios y descritos mecanismos de resistencia. Objetivo: Describir los mecanismos de resistencia al fluconazol expresados por la especie Candida glabrata, con la intención de que sean considerados dentro de las variables de elegibilidad para la intervención. Método: Se realizó una revisión integrativa utilizando la pregunta orientadora: ¿cuáles son los mecanismos de resistencia al fluconazol expresados por la especie Candida glabrata? Veintinueve estudios obtenidos de la base de datos PubMed cumplieron los criterios del análisis crítico propuesto por el instrumento PRISMA, utilizado para la selección de los artículos incluidos para su revisión en este manuscrito. Las categorías bajo las cuales se organizaron los elementos de análisis fueron: sobrexpresión de bombas de eflujo y modificaciones en la enzima lanosterol 14-alfa-desmetilasa. Resultados: Los mecanismos de resistencia al fluconazol expresados por Candida glabrata están determinados principalmente por la regulación a la alza de bombas de adenosina-trifosfato Binding Cassette (ABC) y por la modificación del punto de unión con su blanco farmacológico: la enzima lanosterol 14-alfa-desmetilasa. Conclusión: Los mecanismos de resistencia expresados por Candida glabrata se asocian con la modificación estructural de la diana farmacológica y la sobreexpresión de bombas de eflujo de manera diferencial a otras especies. Se sugiere que Candida glabrata es intrínsecamente menos susceptible al fluconazol.
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18
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Navarro-Rodríguez P, Martin-Vicente A, López-Fernández L, Guarro J, Capilla J. Expression of ERG11 and efflux pump genes CDR1, CDR2 and SNQ2 in voriconazole susceptible and resistant Candida glabrata strains. Med Mycol 2020; 58:30-38. [DOI: 10.1093/mmy/myz014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 11/12/2022] Open
Abstract
AbstractCandida glabrata causes difficult to treat invasive candidiasis due to its antifungal resistance, mainly to azoles. The aim of the present work was to study the role of the genes ERG11, CDR1, CDR2, and SNQ2 on the resistance to voriconazole (VRC) in a set of C. glabrata strains with known in vitro and in vivo susceptibility to this drug. Eighteen clinical isolates of C. glabrata were exposed in vitro to VRC, and the expression of the cited genes was quantified by real time quantitative polymerase chain reaction (q-PCR). In addition, the ERG11 gene was amplified and sequenced to detect possible mutations. Ten synonymous mutations were found in 15 strains, two of them being reported for the first time; however, no amino acid changes were detected. ERG11 and CDR1 were the most expressed genes in all the strains tested, while the expression of CDR2 and SNQ2 was modest. Our results show that gene expression does not directly correlate with the VRC MIC. In addition, the expression profiles of ERG11 and efflux pump genes did not change consistently after exposure to VRC. Although individual analysis did not result in a clear correlation between MIC and gene expression, we did observe an increase in ERG11 and CDR1 expression in resistant strains. It is of interest that considering both in vitro and in vivo results, the slight increase in such gene expression correlates with the observed resistance to VRC.
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Affiliation(s)
- Patricia Navarro-Rodríguez
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Adela Martin-Vicente
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Loida López-Fernández
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Josep Guarro
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Javier Capilla
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
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19
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Benedetti VP, Savi DC, Aluizio R, Adamoski D, Kava V, Galli-Terasawa LV, Glienke C. ERG11 gene polymorphisms and susceptibility to fluconazole in Candida isolates from diabetic and kidney transplant patients. Rev Soc Bras Med Trop 2019; 52:e20180473. [PMID: 30843968 DOI: 10.1590/0037-8682-0473-2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/25/2019] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Candidiasis is the most frequent opportunistic mycosis in humans and can cause mortality, particularly in immunodeficient patients. One major concern is the increasing number of infections caused by drug-resistant Candidas trains, as these cannot be efficiently treated with standard therapeutics. The most common mechanism of fluconazole resistance in Candida is mutation of ERG11, a gene involved in the biosynthesis of ergosterol, a compound essential for cell integrity and membrane function. METHODS Based on this knowledge, we investigated polymorphisms in the ERG11 gene of 3 Candida species isolated from immunocompromised and immunocompetent patients. In addition, we correlated the genetic data with the fluconazole susceptibility profile of the Candida isolates. RESULTS A total of 80 Candida albicans, 8 Candida tropicalis and 6 Candida glabrata isolates were obtained from the saliva of diabetic, kidney transplant and immunocompetent patients. Isolates were considered susceptible to fluconazole if the minimum inhibitory concentration was lower than 8 μg/mL. The amino acid mutations F105L, D116E, K119N, S137L, and K128T were observed in C. albicans isolates, and T224C and G263A were found in C. tropicalis isolates. CONCLUSIONS Despite the high number of polymorphisms observed, the mutations occurred in regions that are not predicted to interfere with ergosterol synthesis, and therefore are not related to fluconazole resistance.
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Affiliation(s)
- Volmir Pitt Benedetti
- Departamento de Microbiologia da Universidade Paranaense, Francisco Beltrão, PR, Brasil.,Departamento de Patologia Básica, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | | | - Rodrigo Aluizio
- Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | - Douglas Adamoski
- Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | - Vanessa Kava
- Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | | | - Chirlei Glienke
- Departamento de Patologia Básica, Universidade Federal do Paraná, Curitiba, PR, Brasil.,Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
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20
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Sharma J, Rosiana S, Razzaq I, Shapiro RS. Linking Cellular Morphogenesis with Antifungal Treatment and Susceptibility in Candida Pathogens. J Fungi (Basel) 2019; 5:E17. [PMID: 30795580 PMCID: PMC6463059 DOI: 10.3390/jof5010017] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023] Open
Abstract
Fungal infections are a growing public health concern, and an increasingly important cause of human mortality, with Candida species being amongst the most frequently encountered of these opportunistic fungal pathogens. Several Candida species are polymorphic, and able to transition between distinct morphological states, including yeast, hyphal, and pseudohyphal forms. While not all Candida pathogens are polymorphic, the ability to undergo morphogenesis is linked with the virulence of many of these pathogens. There are also many connections between Candida morphogenesis and antifungal drug treatment and susceptibility. Here, we review how Candida morphogenesis-a key virulence trait-is linked with antifungal drugs and antifungal drug resistance. We highlight how antifungal therapeutics are able to modulate morphogenesis in both sensitive and drug-resistant Candida strains, the shared signaling pathways that mediate both morphogenesis and the cellular response to antifungal drugs and drug resistance, and the connection between Candida morphology, drug resistance, and biofilm growth. We further review the development of anti-virulence drugs, and targeting Candida morphogenesis as a novel therapeutic strategy to target fungal pathogens. Together, this review highlights important connections between fungal morphogenesis, virulence, and susceptibility to antifungals.
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Affiliation(s)
- Jehoshua Sharma
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Sierra Rosiana
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Iqra Razzaq
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
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21
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Pais P, Galocha M, Viana R, Cavalheiro M, Pereira D, Teixeira MC. Microevolution of the pathogenic yeasts Candida albicans and Candida glabrata during antifungal therapy and host infection. MICROBIAL CELL 2019; 6:142-159. [PMID: 30854392 PMCID: PMC6402363 DOI: 10.15698/mic2019.03.670] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Infections by the pathogenic yeasts Candida albicans and Candida glabrata are among the most common fungal diseases. The success of these species as human pathogens is contingent on their ability to resist antifungal therapy and thrive within the human host. C. glabrata is especially resilient to azole antifungal treatment, while C. albicans is best known for its wide array of virulence features. The core mechanisms that underlie antifungal resistance and virulence in these pathogens has been continuously addressed, but the investigation on how such mechanisms evolve according to each environment is scarcer. This review aims to explore current knowledge on micro-evolution experiments to several treatment and host-associated conditions in C. albicans and C. glabrata. The analysis of adaptation strategies that evolve over time will allow to better understand the mechanisms by which Candida species are able to achieve stable phenotypes in real-life scenarios, which are the ones that should constitute the most interesting drug targets.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Romeu Viana
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Mafalda Cavalheiro
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Diana Pereira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Miguel Cacho Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
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22
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Spettel K, Barousch W, Makristathis A, Zeller I, Nehr M, Selitsch B, Lackner M, Rath PM, Steinmann J, Willinger B. Analysis of antifungal resistance genes in Candida albicans and Candida glabrata using next generation sequencing. PLoS One 2019; 14:e0210397. [PMID: 30629653 PMCID: PMC6328131 DOI: 10.1371/journal.pone.0210397] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/21/2018] [Indexed: 12/13/2022] Open
Abstract
Introduction/Objectives An increase in antifungal resistant Candida strains has been reported in recent years. The aim of this study was to detect mutations in resistance genes of azole-resistant, echinocandin-resistant or multi-resistant strains using next generation sequencing technology, which allows the analysis of multiple resistance mechanisms in a high throughput setting. Methods Forty clinical Candida isolates (16 C. albicans and 24 C. glabrata strains) with MICs for azoles and echinocandins above the clinical EUCAST breakpoint were examined. The genes ERG11, ERG3, TAC1 and GSC1 (FKS1) in C. albicans, as well as ERG11, CgPDR1, FKS1 and FKS2 in C. glabrata were sequenced. Results Fifty-four different missense mutations were identified, 13 of which have not been reported before. All nine echinocandin-resistant Candida isolates showed mutations in the hot spot (HS) regions of FKS1, FKS2 or GSC1. In ERG3 two homozygous premature stop codons were identified in two highly azole-resistant and moderately echinocandin-resistant C. albicans strains. Seven point mutations in ERG11 were determined in azole-resistant C. albicans whereas in azole-resistant C. glabrata, no ERG11 mutations were detected. In 10 out of 13 azole-resistant C. glabrata, 12 different potential gain-of-function mutations in the transcription factor CgPDR1 were verified, which are associated with an overexpression of the efflux pumps CDR1/2. Conclusion This study showed that next generation sequencing allows the thorough investigation of a large number of isolates more cost efficient and faster than conventional Sanger sequencing. Targeting different resistance genes and a large sample size of highly resistant strains allows a better determination of the relevance of the different mutations, and to differentiate between causal mutations and polymorphisms.
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Affiliation(s)
- Kathrin Spettel
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Barousch
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Athanasios Makristathis
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Iris Zeller
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Marion Nehr
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Brigitte Selitsch
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Michaela Lackner
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter-Michael Rath
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Joerg Steinmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, Paracelsus Medical University, Nuremberg, Germany
| | - Birgit Willinger
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
- * E-mail:
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23
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Zhang J, Li L, Lv Q, Yan L, Wang Y, Jiang Y. The Fungal CYP51s: Their Functions, Structures, Related Drug Resistance, and Inhibitors. Front Microbiol 2019; 10:691. [PMID: 31068906 PMCID: PMC6491756 DOI: 10.3389/fmicb.2019.00691] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 03/19/2019] [Indexed: 12/18/2022] Open
Abstract
CYP51 (Erg11) belongs to the cytochrome P450 monooxygenase (CYP) superfamily and mediates a crucial step of the synthesis of ergosterol, which is a fungal-specific sterol. It is also the target of azole drugs in clinical practice. In recent years, researches on fungal CYP51 have stepped into a new stage attributing to the discovery of crystal structures of the homologs in Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. This review summarizes the functions, structures of fungal CYP51 proteins, and the inhibitors targeting these homologs. In particular, several drug-resistant mechanisms associated with the fungal CYP51s are introduced. The sequences and crystal structures of CYP51 proteins in different fungal species are also compared. These will provide new insights for the advancement of research on antifungal agents.
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Affiliation(s)
- Jingxiang Zhang
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Liping Li
- Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Department of Pharmacology, Tongji University School of Medicine, Shanghai, China
| | - Quanzhen Lv
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Lan Yan
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
- *Correspondence: Lan Yan, Yan Wang, Yuanying Jiang,
| | - Yan Wang
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
- *Correspondence: Lan Yan, Yan Wang, Yuanying Jiang,
| | - Yuanying Jiang
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
- Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Department of Pharmacology, Tongji University School of Medicine, Shanghai, China
- *Correspondence: Lan Yan, Yan Wang, Yuanying Jiang,
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24
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Ksiezopolska E, Gabaldón T. Evolutionary Emergence of Drug Resistance in Candida Opportunistic Pathogens. Genes (Basel) 2018; 9:genes9090461. [PMID: 30235884 PMCID: PMC6162425 DOI: 10.3390/genes9090461] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/08/2023] Open
Abstract
Fungal infections, such as candidiasis caused by Candida, pose a problem of growing medical concern. In developed countries, the incidence of Candida infections is increasing due to the higher survival of susceptible populations, such as immunocompromised patients or the elderly. Existing treatment options are limited to few antifungal drug families with efficacies that vary depending on the infecting species. In this context, the emergence and spread of resistant Candida isolates are being increasingly reported. Understanding how resistance can evolve within naturally susceptible species is key to developing novel, more effective treatment strategies. However, in contrast to the situation of antibiotic resistance in bacteria, few studies have focused on the evolutionary mechanisms leading to drug resistance in fungal species. In this review, we will survey and discuss current knowledge on the genetic bases of resistance to antifungal drugs in Candida opportunistic pathogens. We will do so from an evolutionary genomics perspective, focusing on the possible evolutionary paths that may lead to the emergence and selection of the resistant phenotype. Finally, we will discuss the potential of future studies enabled by current developments in sequencing technologies, in vitro evolution approaches, and the analysis of serial clinical isolates.
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Affiliation(s)
- Ewa Ksiezopolska
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.
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25
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Enhanced Efflux Pump Activity in Old Candida glabrata Cells. Antimicrob Agents Chemother 2018; 62:AAC.02227-17. [PMID: 29311061 DOI: 10.1128/aac.02227-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/01/2018] [Indexed: 12/11/2022] Open
Abstract
We investigated the effect of replicative aging on antifungal resistance in Candida glabrata Our studies demonstrate significantly increased transcription of ABC transporters and efflux pump activity in old versus young C. glabrata cells of a fluconazole-sensitive and -resistant strain. In addition, higher tolerance to killing by micafungin and amphotericin B was noted and is associated with higher transcription of glucan synthase gene FKS1 and lower ergosterol content in older cells.
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26
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Berkow EL, Lockhart SR. Fluconazole resistance in Candida species: a current perspective. Infect Drug Resist 2017; 10:237-245. [PMID: 28814889 PMCID: PMC5546770 DOI: 10.2147/idr.s118892] [Citation(s) in RCA: 288] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Candida albicans and the emerging non-albicans Candida spp. have significant clinical relevance among many patient populations. Current treatment guidelines include fluconazole as a primary therapeutic option for the treatment of these infections, but it is only fungistatic against Candida spp. and both inherent and acquired resistance to fluconazole have been reported. Such mechanisms of resistance include increased drug efflux, alteration or increase in the drug target, and development of compensatory pathways for producing the target sterol, ergosterol. While many mechanisms of resistance observed in C. albicans are also found in the non-albicans species, there are also important and unexpected differences between species. Furthermore, mechanisms of fluconazole resistance in emerging Candida spp., including the global health threat Candida auris, are largely unknown. In order to preserve the utility of one of our fundamental antifungal drugs, fluconazole, it is essential that we fully appreciate the manner by which Candida spp. manifest resistance to it.
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Affiliation(s)
- Elizabeth L Berkow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
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27
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Whaley SG, Berkow EL, Rybak JM, Nishimoto AT, Barker KS, Rogers PD. Azole Antifungal Resistance in Candida albicans and Emerging Non- albicans Candida Species. Front Microbiol 2017; 7:2173. [PMID: 28127295 PMCID: PMC5226953 DOI: 10.3389/fmicb.2016.02173] [Citation(s) in RCA: 410] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/28/2016] [Indexed: 12/15/2022] Open
Abstract
Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species.
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Affiliation(s)
- Sarah G Whaley
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Elizabeth L Berkow
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Jeffrey M Rybak
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Andrew T Nishimoto
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Katherine S Barker
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - P David Rogers
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science CenterMemphis, TN, USA; Center for Pediatric Pharmacokinetics and Therapeutics, University of Tennessee Health Science CenterMemphis, TN, USA
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