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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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Wang F, Ge D, Wang L, Li N, Chen H, Zhang Z, Zhu W, Wang S, Liang W. Rapid and sensitive recombinase polymerase amplification combined with lateral flow strips for detecting Candida albicans. Anal Biochem 2021; 633:114428. [PMID: 34678249 DOI: 10.1016/j.ab.2021.114428] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 10/13/2021] [Accepted: 10/16/2021] [Indexed: 12/30/2022]
Abstract
Owing to modern lifestyles and increasing amounts of medical intervention, clinical infections caused by conditionally pathogenic fungi are becoming increasingly serious. Among these, Candida albicans is the most common. Therefore, the rapid and accurate detection of this pathogenic fungus is important to guiding the selection of clinical therapeutic agents. Recombinase polymerase amplification (RPA) combined with lateral flow strips (LFS) is a promising molecular detection method with the advantages of rapidity, simplicity of operation and high sensitivity. However, this simplicity brings with it the inherent and non-negligible risk of false-positive signals from primer-dimers. In this study, primer-dependent artifacts were eliminated by using probes in the RPA reaction, introducing specific base substitutions to the primer and probe sequences and analyzing and screening the formation of primer-probe complexes. These measures were rigorously tested for efficacy, leading to the creation of an improved RPA-LFS system. The standardized method enabled the specific detection of C. albicans within 25 min at 37 °C without interference. The system had a detection limit of 1 CFU per reaction without DNA purification or 102 fg genomic DNA/50 μL. The detection sensitivity was not affected by the presence of other fungal DNA. The RPA-LFS method can therefore be used to detect clinical samples, and the results are accurate and consistent in comparison with those obtained using quantitative PCR. This study provides a paradigm for eliminating the risk of false-positive primer dimers in isothermal amplification assays and establishes a simple and easy method for the detection of C. albicans.
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Affiliation(s)
- Fang Wang
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China
| | - Duobao Ge
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China
| | - Lei Wang
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China; School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu, China
| | - Na Li
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China
| | - Huimin Chen
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China
| | - Zhexiong Zhang
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China
| | - Wenjun Zhu
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China
| | - Siming Wang
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China.
| | - Wei Liang
- Department of Central Laboratory, the Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Affiliated to Bengbu Medical College, Lianyungang, 222000, Jiangsu, China.
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Gabaldón T, Gómez-Molero E, Bader O. Molecular Typing of Candida glabrata. Mycopathologia 2019; 185:755-764. [PMID: 31617105 DOI: 10.1007/s11046-019-00388-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/21/2019] [Indexed: 12/17/2022]
Abstract
The yeast Candida glabrata has emerged, second only to Candida albicans, to be one of the most frequently isolated fungi in clinical specimen from human. Its frequent resistance towards azole antifungal drugs and the high capacity to form biofilms on indwelling catheters of individual isolates render it an often difficult to treat pathogen. Hence, there is a notably increasing scientific and clinical interest in this species. This has led to the development of a variety of molecular tools for genetic modification, strain collections, and last but not least different approaches to analyse the population structure among isolates of different geographical and clinical contexts. Often, these are used to study correlations (or the absence thereof) with different pathogenicity, virulence, or drug resistance traits. Three molecular methods have been used to type within the C. glabrata population on a genetic level by multiple studies: multi-locus sequence typing, microsatellite length polymorphisms, and clustering of whole-genome sequencing data, and these are subject of this review.
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Affiliation(s)
- Toni Gabaldón
- Comparative Genomics Group, Life Science Programme, Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Institute of Research in Biomedicine (IRB), Barcelona, Spain
- Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| | - Emilia Gómez-Molero
- Institute for Medical Microbiology, University Medical Center Göttingen, Kreuzbergring 57, 37075, Göttingen, Germany
| | - Oliver Bader
- Institute for Medical Microbiology, University Medical Center Göttingen, Kreuzbergring 57, 37075, Göttingen, Germany.
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