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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 Y, Xu J, Ben Abid F, Salah H, Sundararaju S, Al Ismail K, Wang K, Sara Matthew L, Taj-Aldeen S, Ibrahim EB, Tang P, Perez-Lopez A, Tsui CKM. Population genomic analyses reveal high diversity, recombination and nosocomial transmission among Candida glabrata ( Nakaseomyces glabrata) isolates causing invasive infections. Microb Genom 2024; 10:001179. [PMID: 38226964 PMCID: PMC10868614 DOI: 10.1099/mgen.0.001179] [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: 10/10/2023] [Accepted: 12/21/2023] [Indexed: 01/17/2024] Open
Abstract
Candida glabrata is a commensal yeast of the gastrointestinal tract and skin of humans. However, it causes opportunistic infections in immunocompromised patients, and is the second most common Candida pathogen causing bloodstream infections. Although there are many studies on the epidemiology of C. glabrata infections, the fine- and large-scale geographical nature of C. glabrata remain incompletely understood. Here we investigated both the fine- and large-scale population structure of C. glabrata through genome sequencing of 80 clinical isolates obtained from six tertiary hospitals in Qatar and by comparing with global collections. Our fine-scale analyses revealed high genetic diversity within the Qatari population of C. glabrata and identified signatures of recombination, inbreeding and clonal expansion within and between hospitals, including evidence for nosocomial transmission among coronavirus disease 2019 (COVID-19) patients. In addition to signatures of recombination at the population level, both MATa and MATα alleles were detected in most hospitals, indicating the potential for sexual reproduction in clinical environments. Comparisons with global samples showed that the Qatari C. glabrata population was very similar to those from other parts of the world, consistent with the significant role of recent anthropogenic activities in shaping its population structure. Genome-wide association studies identified both known and novel genomic variants associated with reduced susceptibilities to fluconazole, 5-flucytosine and echinocandins. Together, our genomic analyses revealed the diversity, transmission patterns and antifungal drug resistance mechanisms of C. glabrata in Qatar as well as the relationships between Qatari isolates and those from other parts of the world.
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Affiliation(s)
- Yue Wang
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Fatma Ben Abid
- Department of Medicine, Division of Infectious Diseases, Hamad Medical Corporation, Doha, Qatar
- Weill Cornell Medicine-Qatar, Doha, Qatar
- Communicable Disease Centre, Hamad Medical Corporation, Doha, Qatar
| | - Husam Salah
- Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | | | - Khalil Al Ismail
- Communicable Disease Centre, Hamad Medical Corporation, Doha, Qatar
| | - Kun Wang
- Research Department, Sidra Medicine, Doha, Qatar
| | | | - Saad Taj-Aldeen
- Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Emad B. Ibrahim
- Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Patrick Tang
- Weill Cornell Medicine-Qatar, Doha, Qatar
- Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Andres Perez-Lopez
- Weill Cornell Medicine-Qatar, Doha, Qatar
- Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Clement K. M. Tsui
- Division of Microbiology, Department of Pathology, Sidra Medicine, Doha, Qatar
- Infectious Diseases Research Laboratory, National Center for Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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Dunaiski CM, Kock MM, Jung H, Peters RPH. Importance of Candida infection and fluconazole resistance in women with vaginal discharge syndrome in Namibia. Antimicrob Resist Infect Control 2022; 11:104. [PMID: 35971143 PMCID: PMC9377096 DOI: 10.1186/s13756-022-01143-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vaginal discharge syndrome (VDS) is a common condition. Clinical management targets sexually transmitted infections (STIs) and bacterial vaginosis (BV); there is limited focus on Candida infection as cause of VDS. Lack of Candida treatment coverage and, if present, antifungal resistance may result in VDS treatment failure. This study aimed to determine the prevalence of Candida infection, antifungal resistance, and coinfections in Namibian women with VDS. METHODS A cross-sectional study was performed using 253 vaginal swabs from women with VDS in Namibia. Demographic data was collected, and phenotypic and molecular detection of Candida species was performed followed by fluconazole susceptibility testing of Candida isolates. BV was diagnosed using Nugent score microscopy; molecular detection of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis was performed. RESULTS Candida species was detected in 110/253 women (43%). Ninety women (36%) had Candida albicans and 24 (9.5%) had non-albicans Candida species. The non-albicans species detected were 19 (17%) Candida glabrata, 4.0 (3.5%) Candida krusei, and 1.0 (0.9%) Candida parapsilosis. Candida albicans were more frequently isolated in younger (p = 0.004) and pregnant women (p = 0.04) compared to non-albicans Candida species. Almost all (98%) Candida albicans isolates were susceptible to fluconazole while all non-albicans Candida species were fluconazole resistant. STIs were diagnosed in 92 women (36%): 30 (12%) with C. trachomatis, 11 (4.3%) N. gonorrhoeae, and 70 (28%) T. vaginalis; 98 (39%) women had BV. Candida infection alone was diagnosed in 30 women (12%), combined with STIs in 42 women (17%) and was concurrent with BV in 38 women (15%). Candida infection was more often detected in swabs from women without C. trachomatis detected (6.4% vs. 16%; OR 0.30; 95% CI 0.10-0.77, p = 0.006). CONCLUSIONS The high prevalence of Candida infection, especially those due to non-albicans Candida species that are resistant to fluconazole, is a great concern in our setting and may lead to poor treatment outcomes. Access to microbiological testing for Candida species in the context of syndromic management is warranted.
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Affiliation(s)
- Cara M Dunaiski
- Department of Health and Applied Sciences, Namibia University of Sciences and Technology, Windhoek, Namibia
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa
| | - Marleen M Kock
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa
- Tshwane Academic Division, National Health Laboratory Service, Pretoria, South Africa
| | - Hyunsul Jung
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa
| | - Remco P H Peters
- Department of Medical Microbiology, University of Pretoria, Prinshof Campus, Pathology Building, Room 3-11, Pretoria, South Africa.
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa.
- Research Unit, Foundation for Professional Development, East London, South Africa.
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