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Wang Y, Wan X, Zhao L, Jin P, Zhang J, Zhou X, Ye N, Wang X, Pan Y, Xu L. Clonal aggregation of fluconazole-resistant Candida tropicalis isolated from sterile body fluid specimens from patients in Hefei, China. Med Mycol 2023; 61:myad097. [PMID: 37777835 DOI: 10.1093/mmy/myad097] [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: 06/07/2023] [Revised: 08/28/2023] [Accepted: 09/27/2023] [Indexed: 10/02/2023] Open
Abstract
Candida tropicalis, a human conditionally pathogenic yeast, is distributed globally, especially in Asia-Pacific. The increasing morbidity and azole resistance of C. tropicalis have made clinical treatment difficult. The correlation between clonality and antifungal susceptibility of clinical C. tropicalis isolates has been reported. To study the putative correlation in C. tropicalis isolated from normally sterile body fluid specimens and explore the distinct clonal complex (CC) in Hefei, 256 clinical C. tropicalis isolates were collected from four teaching hospitals during 2016-2019, of which 30 were fluconazole-resistant (FR). Genetic profiles of 63 isolates, including 30 FR isolates and 33 fluconazole-susceptible (FS) isolates, were characterized using multilocus sequence typing (MLST). Phylogenetic analysis of the data was conducted using UPGMA (unweighted pair group method with arithmetic averages) and the minimum spanning tree algorithm. MLST clonal complexes (CCs) were analyzed using the goeBURST package. Among 35 differentiated diploid sequence types (DSTs), 16 DSTs and 1 genotype were identified as novel. A total of 35 DSTs were assigned to five major CCs based on goeBURST analysis. CC1 (containing DST376, 505, 507, 1221, 1222, 1223, 1226, and 1229) accounted for 86.7% (26/30) of the FR isolates. However, the genetic relationships among the FS isolates were relatively decentralized. The local FR CC1 belongs to a large fluconazole non-susceptible CC8 in global isolates, of which the putative founder genotype was DST225. The putative correlation between MLST types and antifungal susceptibility of clinical C. tropicalis isolates in Hefei showed that DSTs are closely related to FR clones.
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Affiliation(s)
- Ying Wang
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei, China
| | - Xin Wan
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei, China
| | - Li Zhao
- Department of Urology, Anhui Zhongke Gengjiu Hospital, Hefei, China
| | - Peipei Jin
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei, China
| | - Ju Zhang
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei, China
| | - Xin Zhou
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei, China
| | - Naifang Ye
- Department of Clinical Laboratory Medicine, The Second Hospital of Anhui Medical University, Anhui Medical University, Hefei, China
| | - Xiaowei Wang
- Department of Clinical Laboratory Medicine, The First Hospital of Anhui Medical University, Anhui Medical University, Hefei, China
| | - Yaping Pan
- Department of Clinical Laboratory Medicine, High Tech Branch of The First Hospital of Anhui Medical University, Anhui Medical University, Hefei, China
| | - Liangfei Xu
- Department of Laboratory Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei, China
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Li R, Wu J, He F, Xu Q, Yin K, Li S, Li W, Wei A, Zhang L, Zhang XH, Zhang B. Rational design, synthesis, antifungal evaluation and docking studies of antifungal peptide CGA-N12 analogues based on the target CtKRE9. Bioorg Chem 2023; 132:106355. [PMID: 36669359 DOI: 10.1016/j.bioorg.2023.106355] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/02/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023]
Abstract
Candida tropicalis is a major non-albicans species that causes invasive candidiasis. CGA-N12, an anti-Candida peptide found by our group, disrupted cell wall architecture by inhibiting the activity of the protein killer-resistant 9 (KRE9), a β-1,6-glucan synthase specific to Candida spp. and plants. Herein, a set of CGA-N12 analogues were rationally designed based on the interaction networks between CGA-N12 and C. tropicalis KRE9 (CtKRE9). Seven CGA-N12 analogues with significantly improved antifungal activity against C. tropicalis were screened by reducing the docking energy of CGA-N12 and CtKRE9 and increasing the number of positive charges on CGA-N12 based on a stable three-dimensional model of CtKRE9. CGA-N12 and its analogues exhibited antifungal activity against C. tropicalis and its persist cells; they also inhibited biofilm formation and eradicated preformed biofilms. Compared with fluconazole, they displayed higher activities against the growth of persister cells and more effective preformed biofilm eradication. Among them, CGA-N12-0801, CGA-N12-0902 and CGA-N12-1002 displayed much higher activity and anti-proteinase digestion stability than CGA-N12. Specifically, CGA-N12-0801 was the optimal analogue, with a minimum inhibitory concentration of 3.46 μg/mL and a therapeutic index of 158.07. The results of electronic microscopy observations and KRE9 activity inhibition assays showed that CGA-N12 and its analogues killed C. tropicalis by disrupting the architecture of the cell wall and the integrity of the cell membrane. In conclusion, for the first time, we provide a simple and reliable method for the rational design of antimicrobial peptides and ideal candidates for treating Candida infections that not effectively eliminated by azole drugs.
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Affiliation(s)
- Ruifang Li
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; Key Laboratory of Functional Molecules for Biomedical Research, Henan University of Technology, 450001 Zhengzhou, Henan, PR China.
| | - Jiasha Wu
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; Key Laboratory of Functional Molecules for Biomedical Research, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Fuyang He
- School of Artificial Intelligence and Big Data, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Qingpeng Xu
- College of Information Science and Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Kedong Yin
- College of Information Science and Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Shang Li
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Weitong Li
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Ao Wei
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Lan Zhang
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; Key Laboratory of Functional Molecules for Biomedical Research, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Xin-Hui Zhang
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; Key Laboratory of Functional Molecules for Biomedical Research, Henan University of Technology, 450001 Zhengzhou, Henan, PR China
| | - Beibei Zhang
- College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; Key Laboratory of Functional Molecules for Biomedical Research, Henan University of Technology, 450001 Zhengzhou, Henan, PR China.
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Keighley C, Gall M, van Hal SJ, Halliday CL, Chai LYA, Chew KL, Biswas C, Slavin MA, Meyer W, Sintchenko V, Chen SCA. Whole Genome Sequencing Shows Genetic Diversity, as Well as Clonal Complex and Gene Polymorphisms Associated with Fluconazole Non-Susceptible Isolates of Candida tropicalis. J Fungi (Basel) 2022; 8:jof8090896. [PMID: 36135621 PMCID: PMC9505729 DOI: 10.3390/jof8090896] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/15/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
Resistance to azoles in Candida tropicalis is increasing and may be mediated by genetic characteristics. Using whole genome sequencing (WGS), we examined the genetic diversity of 82 bloodstream C. tropicalis isolates from two countries and one ATCC strain in a global context. Multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP)-based phylogenies were generated. Minimum inhibitory concentrations (MIC) for antifungal agents were determined using Sensititre YeastOne YO10. Eleven (13.2%) isolates were fluconazole-resistant and 17 (20.5%) were classified as fluconazole-non susceptible (FNS). Together with four Canadian isolates, the genomes of 12 fluconazole-resistant (18 FNS) and 69 fluconazole-susceptible strains were examined for gene mutations associated with drug resistance. Fluconazole-resistant isolates contained a mean of 56 non-synonymous SNPs per isolate in contrast to 36 SNPs in fluconazole-susceptible isolates (interquartile range [IQR] 46−59 vs. 31−48 respectively; p < 0.001). Ten of 18 FNS isolates contained missense ERG11 mutations (amino acid substitutions S154F, Y132F, Y257H). Two echinocandin-non susceptible isolates had homozygous FKS1 mutations (S30P). MLST identified high genetic diversity with 61 diploid sequence types (DSTs), including 53 new DSTs. All four isolates in DST 773 were fluconazole-resistant within clonal complex 2. WGS showed high genetic variation in invasive C. tropicalis; azole resistance was distributed across different lineages but with DST 773 associated with in vitro fluconazole resistance.
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Affiliation(s)
- Caitlin Keighley
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, NSW 2145, Australia
- Centre for Infectious Diseases and Microbiology, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead Hospital, Sydney, NSW 2145, Australia
- Correspondence: (C.K.); (M.G.)
| | - Mailie Gall
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, NSW 2145, Australia
- Correspondence: (C.K.); (M.G.)
| | - Sebastiaan J. van Hal
- Department of Infectious Diseases and Microbiology, New South Wales Health Pathology, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| | - Catriona L. Halliday
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, NSW 2145, Australia
| | - Louis Yi Ann Chai
- Division of Infectious Diseases, Department of Medicine, National University Health System, Singapore 119228, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Kean Lee Chew
- Division of Infectious Diseases, Department of Medicine, National University Health System, Singapore 119228, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
- Department of Laboratory Medicine, National University Health System, Singapore 119074, Singapore
| | - Chayanika Biswas
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, NSW 2145, Australia
| | - Monica A. Slavin
- Department of Infectious Diseases, National Centre for Infections in Cancer, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia
| | - Wieland Meyer
- Centre for Infectious Diseases and Microbiology, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead Hospital, Sydney, NSW 2145, Australia
- Molecular Mycology Research Laboratory, Center for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW 2145, Australia
- Research and Education Network, Western Sydney Local Health District, Westmead Hospital, Westmead, NSW 2145, Australia
- Curtin Medical School, Curtin University, Bentley, WA 6102, Australia
| | - Vitali Sintchenko
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, NSW 2145, Australia
- Centre for Infectious Diseases and Microbiology, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead Hospital, Sydney, NSW 2145, Australia
- Molecular Mycology Research Laboratory, Center for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, NSW 2145, Australia
| | - Sharon C. A. Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, NSW 2145, Australia
- Centre for Infectious Diseases and Microbiology, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead Hospital, Sydney, NSW 2145, Australia
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Extensive Diversity and Prevalent Fluconazole Resistance among Environmental Yeasts from Tropical China. Genes (Basel) 2022; 13:genes13030444. [PMID: 35327998 PMCID: PMC8954247 DOI: 10.3390/genes13030444] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 02/26/2022] [Accepted: 02/27/2022] [Indexed: 02/05/2023] Open
Abstract
Yeasts play important roles in both the environment and in human welfare. While some environmental yeasts positively contribute to nutrient cycling and food production, a significant number of yeast species are opportunistic human pathogens, including several that are tolerant/resistant to commonly used antifungal drugs. At present, most of our understanding of environmental yeasts has come from a few terrestrial environments in selected geographic regions. Relatively little is known about yeast diversity in tropical environments and their potential impacts on human health. Here, we characterize culturable yeasts in 968 environmental samples from eight regions in tropical China. Among the 516 soil, 273 freshwater, and 179 seawater samples, 71.5%, 85.7%, and 43.6% contained yeasts, respectively. A total of 984 yeast isolates were analyzed for their DNA barcode sequences and their susceptibilities to fluconazole. DNA sequence comparisons revealed that the 984 yeast isolates likely belonged to 144 species, including 106 known species and 38 putative novel species. About 38% of the 984 isolates belonged to known human pathogens and the most common species was Candida tropicalis, accounting for 21% (207/984) of all isolates. Further analyses based on multi-locus sequence typing revealed that some of these environmental C. tropicalis shared identical genotypes with clinical isolates previously reported from tropical China and elsewhere. Importantly, 374 of the 984 (38%) yeast isolates showed intermediate susceptibility or resistance to fluconazole. Our results suggest that these environmental yeasts could have significant negative impacts on human health.
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Song N, Kan S, Pang Q, Mei H, Zheng H, Li D, Cui F, Lv G, An R, Li P, Xiong Z, Fan S, Zhang M, Chen Y, Qiao Q, Liang X, Cui M, Li D, Liao Q, Li X, Liu W. A prospective study on vulvovaginal candidiasis: multicentre molecular epidemiology of pathogenic yeasts in China. J Eur Acad Dermatol Venereol 2021; 36:566-572. [PMID: 34908189 DOI: 10.1111/jdv.17874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 11/17/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND Vulvovaginal candidiasis (VVC) is frequent in women of reproductive age, but very limited data are available on the epidemiology in cases of VVC in China. OBJECTIVES The current study has been conducted to reveal the prevalence, species distribution of yeast causing VVC and molecular genetics of Candida albicans in China. METHODS Vaginal swabs were collected from 543 VVC outpatients recruited in 12 hospitals in China between September 2017 and March 2018. They were preliminarily incubated on Sabouraud dextrose agar and then positive subjects of which were then transmitted to our institute for further identification. CHROMagar™ was used to isolate Candida species, and all isolates were finally identified by DNA sequencing. Multilocus sequence typing (MLST) was used to analyse phylogenetic relationships of the various C. albicans isolates. RESULTS Eleven different yeast species were identified in 543 isolates, among which C. albicans (84.7%) was the most frequent, followed by C. glabrata (8.7%). We obtained 117 unique diploid sequence types from 451 clinical C. albicans isolates and 92 isolates (20.4%) belonged to a New Clade. All the strains appearing in the New Clade were from northern China and they were isolated from non-recurrent VVC. CONCLUSIONS Our findings suggest that C. albicans are still the main cause of VVC in China and the majority of C. albicans isolates belongs to Clade 1 with DST 79 and DST 45 being two most common. Moreover, the New Clade revealed in our study seems to be specific to northern China.
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Affiliation(s)
- N Song
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - S Kan
- Shanghai Skin Disease Hospital, Department of Medical Mycology, Tongji University School of Medicine, Shanghai, China
| | - Q Pang
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - H Mei
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - H Zheng
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - D Li
- Department of Microbiology/Immunology, Georgetown University, Washington, DC, USA
| | - F Cui
- Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - G Lv
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - R An
- The First Affiliated Teaching Hospital of Xi'an Jiaotong University, Xi'an, China
| | - P Li
- Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, China
| | - Z Xiong
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - S Fan
- Peking University Shenzhen Hospital, Shenzhen, China
| | - M Zhang
- The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Y Chen
- The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Q Qiao
- The Affiliated Hospital of Inner Mongolia Medical University, Huhehaote, China
| | - X Liang
- Peking University People's Hospital, Beijing, China
| | - M Cui
- Department of Obstetrics and Gynecology, The Second Hospital of Jilin University, Changchun, China
| | - D Li
- The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Q Liao
- Department of Obstetrics and Gynecology, Beijing Tsinghua Changgung Hospital, School of Clinical Medical, Tsinghua University, Beijing, China
| | - X Li
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - W Liu
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China.,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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Zhou D, Xu J, Dong J, Li H, Wang D, Gu J, Zhang KQ, Zhang Y. Historical Differentiation and Recent Hybridization in Natural Populations of the Nematode-Trapping Fungus Arthrobotrys oligospora in China. Microorganisms 2021; 9:1919. [PMID: 34576814 PMCID: PMC8465350 DOI: 10.3390/microorganisms9091919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 01/10/2023] Open
Abstract
Maintaining the effects of nematode-trapping fungi (NTF) agents in order to control plant-parasitic nematodes (PPNs) in different ecological environments has been a major challenge in biological control applications. To achieve such an objective, it is important to understand how populations of the biocontrol agent NTF are geographically and ecologically structured. A previous study reported evidence for ecological adaptation in the model NTF species Arthrobotrys oligospora. However, their large-scale geographic structure, patterns of gene flow, their potential phenotypic diversification, and host specialization remain largely unknown. In this study, we developed a new panel of 20 polymorphic short tandem repeat (STR) markers and analyzed 239 isolates of A. oligospora from 19 geographic populations in China. In addition, DNA sequences at six nuclear gene loci and strain mating types (MAT) were obtained for these strains. Our analyses suggest historical divergence within the A. oligospora population in China. The genetically differentiated populations also showed phenotypic differences that may be related to their ecological adaptations. Interestingly, our analyses identified evidence for recent dispersion and hybridization among the historically subdivided geographic populations in nature. Together, our results indicate a changing population structure of A. oligospora in China and that care must be taken in selecting the appropriate strains as biocontrol agents that can effectively reproduce in agriculture soil while maintaining their nematode-trapping ability.
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Affiliation(s)
- Duanyong Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
- School of Biology and Chemistry, Xingyi Normal University for Nationalities, Xingyi 562400, China
| | - Jianping Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Jianyong Dong
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Haixia Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Da Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Juan Gu
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
| | - Ying Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
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The Interplay Between Neutral and Adaptive Processes Shapes Genetic Variation During Candida Species Evolution. CURRENT CLINICAL MICROBIOLOGY REPORTS 2021. [DOI: 10.1007/s40588-021-00171-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Wu J, Gan C, Li J, Liu Y, Chen Z, Zhang Y, Yi G, Sui J, Xu J. Species Diversity and Antifungal Susceptibilities of Oral Yeasts from Patients with Head and Neck Cancer. Infect Drug Resist 2021; 14:2279-2288. [PMID: 34168468 PMCID: PMC8219225 DOI: 10.2147/idr.s316368] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/29/2021] [Indexed: 12/14/2022] Open
Abstract
Purpose To investigate the colonization and susceptibility to antifungal drugs of oral yeasts in head and neck cancer patients in Hainan, China. Methods Oral mucosa samples from 211 head and neck cancer patients were collected. Oral yeasts were isolated and identified to species by rDNA ITS sequencing. The susceptibilities of all yeasts to amphotericin B, fluconazole, fluorocytosine, itraconazole, and ketoconazole were determined. Results Yeasts were isolated from 124 of the 211 oral swabs. The 124 yeast isolates were classified into following 10 species, from the most frequent to the least frequent, Candida albicans (53.2%), Candida tropicalis (22.6%), Candida krusei (6.5%), Kodamaea ohmeri (5.6%), Candida parapsilosis (4.8%), Hanseniaspora opuntiae (2.4%), Candida metapsilosis (1.6%), Pichia terricola (1.6%), Pichia norvegensis (0.8%), and Trichosporon asahii (0.8%). The overall frequencies of resistance among the yeasts to amphotericin B, fluconazole, flucytosine, itraconazole, and ketoconazole were 4.8%, 8.1%, 16.1%, 9.7%, and 9.7%, respectively. One C. albicans strain and one C. tropicalis strain were tolerant/resistant to all five drugs. Conclusion Given the high prevalence of oral yeast colonization in head and neck cancer patients and the observed resistance of certain yeast isolates to the five antifungal drugs, our results suggest that rapid identification and susceptibility testing should be implemented before antifungal treatment is applied among patients with head and neck cancer in Hainan.
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Affiliation(s)
- Jinyan Wu
- Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China.,Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Chengwen Gan
- Department of Oral Maxillofacial Surgery, Hainan General Hospital, Haikou, Hainan, 570203, People's Republic of China
| | - Jingyuan Li
- Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China.,Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Yiwei Liu
- Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Zhongyao Chen
- Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Yunxia Zhang
- Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China.,Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Guohui Yi
- Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China.,Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Jinlei Sui
- Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China.,Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China
| | - Jianping Xu
- Public Laboratory of Hainan Medical University, Haikou, 571199, Hainan, People's Republic of China.,Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada
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Wang Q, Tang D, Tang K, Guo J, Huang Y, Li C. Multilocus Sequence Typing Reveals Clonality of Fluconazole-Nonsusceptible Candida tropicalis: A Study From Wuhan to the Global. Front Microbiol 2020; 11:554249. [PMID: 33281755 PMCID: PMC7705220 DOI: 10.3389/fmicb.2020.554249] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/26/2020] [Indexed: 12/24/2022] Open
Abstract
Candida tropicalis is a globally distributed human pathogenic yeast, and its increasing resistance to azoles makes clinical treatment difficult. In this study, we investigated the clinical features, azole resistance and genetic relatedness of 87 C. tropicalis isolates from central China and combined with the global database to explore the relationship between genetic information and fluconazole susceptibility. Of the 55 diploid sequence types (DSTs) identified by multilocus sequence typing (MLST), 27 DSTs were new to the C. tropicalis MLST database. Fluconazole-nonsusceptible (FNS) isolates were genetically closely related. goeBURST analysis showed that DST225, DST376, DST506, and DST546 formed a distinct and unique FNS clonal complex (CC) in Wuhan. The local FNS CC belongs to the large FNS CC (CC2) in China, in which the putative founder DST225 has been reported from the environment. The three most prevalent types (DST506, DST525, and DST546) in Wuhan had high minimum inhibitory concentrations (MICs) for antifungal azoles, and the six possible nosocomial transmissions we captured were all FNS strains, most of which were from CC2. Unique FNS CCs have been found in Singapore (CC8) and India (CC17) and are close to China's CC2 in the minimum spanning tree. There were no FNS CCs outside Asia. This study is the first to reveal a significant correlation between genetic information and fluconazole susceptibility worldwide and to trace geographical locations, which is of great value for molecular epidemiological surveillance and azole-resistance study of C. tropicalis globally.
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Affiliation(s)
- Qianyu Wang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Dongling Tang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Kewen Tang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jing Guo
- Department of Clinical Laboratory, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yun Huang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Congrong Li
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
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10
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Wang Q, Li C, Tang D, Tang K. Molecular epidemiology of Candida tropicalis isolated from urogenital tract infections. Microbiologyopen 2020; 9:e1121. [PMID: 32985133 PMCID: PMC7658454 DOI: 10.1002/mbo3.1121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 12/22/2022] Open
Abstract
Candida tropicalis is a common human pathogenic yeast, and its molecular typing is important for studying the population structure and epidemiology of this opportunistic yeast, such as epidemic genotype, population dynamics, nosocomial infection, and drug resistance surveillance. In this study, the antifungal susceptibility test and multilocus sequence typing (MLST) analysis were carried out on C. tropicalis from central China. Among 64 urogenital isolates, 45 diploid sequence types (DST) were found, of which 20 DSTs (44.4%) were new to the central database. The goeBURST analysis showed that CC1 (clonal complex) was the only azole‐resistant (100%, 10/10) cluster in Wuhan, which was composed of DST546, DST225, DST376, and DST506, and most of the strains (90%, 9/10) were isolated from the urinary tract. Potential nosocomial infections were mainly caused by CC1 strains. The azole resistance rate of urinary isolates (50.0%, 21/42) was higher than that of vaginal isolates (27.3%, 6/22). The genotype diversity and novelty of vaginal isolates were higher than those of urinary isolates. C. tropicalis population in Wuhan was genetically diverse and divergent from that seen in other countries. In this study, there were significant differences in genotype and azole susceptibility between urine and vaginal strains. The azole‐resistant cluster (CC1) found in urine is of great significance for the clinical treatment and prevention of nosocomial infection. The newly discovered DSTs will contribute to further study the similarity, genetic relationship, and molecular epidemiology of C. tropicalis worldwide.
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Affiliation(s)
- Qianyu Wang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Congrong Li
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Dongling Tang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Kewen Tang
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
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11
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Tulyaprawat O, Pharkjaksu S, Chongtrakool P, Ngamskulrungroj P. An Association of an eBURST Group With Triazole Resistance of Candida tropicalis Blood Isolates. Front Microbiol 2020; 11:934. [PMID: 32508774 PMCID: PMC7248567 DOI: 10.3389/fmicb.2020.00934] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 04/20/2020] [Indexed: 12/12/2022] Open
Abstract
Candidemia, a bloodstream infection caused by genus Candida, has a high mortality rate. Candida albicans was previously reported to be the most common causative species among candidemia patients. However, during the past 10 years in Thailand, Candida tropicalis has been recovered from blood more frequently than C. albicans. The cause of this shift in the prevalence of Candida spp. remains unexplored. We conducted in vitro virulence studies and antifungal susceptibility profiles of 48 C. tropicalis blood isolates collected during 2015-2017. To compare to global isolates of C. tropicalis, multilocus sequence typing (MLST), a minimum spanning tree, and an eBURST analysis were also conducted. C. tropicalis and C. albicans were the most (47-48.7%) and second-most (21.5-33.9%) common species to be isolated from candidemia patients, respectively. Of the C. tropicalis blood isolates, 29.2, 0, 100, and 93.8% exhibited proteinase activity, phospholipase activity, hemolytic activity, and biofilm formation, respectively. Moreover, 20.8% (10/48) of the isolates were resistant to voriconazole and fluconazole, and also showed high minimum inhibitory concentrations (MICs) to posaconazole and itraconazole. In contrast, most of the isolates were susceptible to anidulafungin (97.9%), micafungin (97.9%), and caspofungin (97.9%), and showed low MICs to amphotericin B (100%) and 5-flucytosine (100%). The MLST identified 22 diploid sequence types. Based on the eBURST analysis and minimum spanning tree, 9 out of 13 members (69.2%) of an eBURST group 3 were resistant to voriconazole and fluconazole, and also showed high MICs to posaconazole and itraconazole. Association analysis revealed the eBURST group 3 was significantly associated with the four triazole resistance (p < 0.001). In conclusion, the eBURST group 3 was associated with the triazole resistance and resistance to many antifungal drugs might be collectively responsible for the prevalence shift.
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Affiliation(s)
| | | | | | - Popchai Ngamskulrungroj
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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12
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Chen PY, Chuang YC, Wu UI, Sun HY, Wang JT, Sheng WH, Lo HJ, Wang HY, Chen YC, Chang SC. Clonality of Fluconazole-Nonsusceptible Candida tropicalis in Bloodstream Infections, Taiwan, 2011-2017. Emerg Infect Dis 2020; 25:1660-1667. [PMID: 31441426 PMCID: PMC6711239 DOI: 10.3201/eid2509.190520] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Candida tropicalis is the leading cause of non-C. albicans candidemia in tropical Asia and Latin America. We evaluated isolates from 344 patients with an initial episode of C. tropicalis candidemia. We found that 58 (16.9%) patients were infected by fluconazole-nonsusceptible (FNS) C. tropicalis with cross resistance to itraconazole, voriconazole, and posaconazole; 55.2% (32/58) of patients were azole-naive. Multilocus sequence typing analysis revealed FNS isolates were genetically closely related, but we did not see time- or place-clustering. Among the diploid sequence types (DSTs), we noted DST225, which has been reported from fruit in Taiwan and hospitals in Beijing, China, as well as DST376 and DST505-7, which also were reported from hospitals in Shanghai, China. Our findings suggest cross-boundary expansion of FNS C. tropicalis and highlight the importance of active surveillance of clinical isolates to detect dissemination of this pathogen and explore potential sources in the community.
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13
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Pham LTT, Pharkjaksu S, Chongtrakool P, Suwannakarn K, Ngamskulrungroj P. A Predominance of Clade 17 Candida albicans Isolated From Hemocultures in a Tertiary Care Hospital in Thailand. Front Microbiol 2019; 10:1194. [PMID: 31258518 PMCID: PMC6587676 DOI: 10.3389/fmicb.2019.01194] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 05/13/2019] [Indexed: 12/24/2022] Open
Abstract
Candida albicans is one of the most common human fungal pathogens. Candidemia has significant mortality globally. No epidemiological study of C. albicans based on multilocus sequence typing (MLST) has been conducted in Thailand. Therefore, MLST was used to study the molecular epidemiology of C. albicans blood strains in a large Thai teaching hospital. In vitro virulence phenotypes and antifungal susceptibility testing by broth microdilution were also conducted. Forty-six C. albicans blood strains from 37 patients were collected from the Department of Microbiology, Siriraj Hospital, in 2016 and 2017. Most patients (71.8%) were more than 60 years old, and the case fatality rate was 54.8%. The male-to-female ratio was 5:3. Thirty-four diploid sequence types (DSTs), including six new DSTs, were identified, with DST2514 (8.7%) and DST2876 (8.7%) as the most common DSTs. Strains were clustered into nine clades. Unlike other studies of C. albicans blood strains in Asia, clade 17 was the most common (13 strains, 28.3%). Sequential allelic changes were evident in sequential strains from one patient. All strains produced phospholipase and hemolysin, while none produced proteinase. The ability to form biofilm was found in 82.6% of the strains. Clade 17 strains showed significantly stronger hemolytic activity than non–clade 17 strains (69.2% versus 27.3%; p = 0.022). However, no significant association existed between clades and patient mortalities. All were susceptible or wild type to anidulafungin (MIC range = 0.015–0.12 and GM = 0.030), micafungin (MIC range = ≤ 0.008–0.015 and GM = 0.008), caspofungin (MIC range = 0.008–0.12 and GM = 0.036), and amphotericin B (MIC range = 0.25–0.5 and GM = 0.381). Only one strain was resistant to voriconazole (MIC range = ≤ 0.008 to ≥ 8 and GM = 0.010) and fluconazole (MIC range = 0.12–16 and GM = 0.398). In conclusion, a high prevalence of clade 17 C. albicans blood strains was found in Thailand, in contrast to other Asian countries. This unique finding might be explained by the strong hemolytic activity that is required for bloodstream infection of C. albicans.
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Affiliation(s)
- Linh Thi Truc Pham
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Thailand
| | - Sujiraphong Pharkjaksu
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Thailand
| | - Piriyaporn Chongtrakool
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Thailand
| | - Kamol Suwannakarn
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Thailand
| | - Popchai Ngamskulrungroj
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Thailand
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14
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Wu JY, Zhou DY, Zhang Y, Mi F, Xu J. Analyses of the Global Multilocus Genotypes of the Human Pathogenic Yeast Candida tropicalis. Front Microbiol 2019; 10:900. [PMID: 31080446 PMCID: PMC6497803 DOI: 10.3389/fmicb.2019.00900] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/09/2019] [Indexed: 12/13/2022] Open
Abstract
Candida tropicalis is a globally distributed human pathogenic yeast, especially prevalent in tropical and sub-tropical regions. Over the last several decades, a large number of studies have been published on the genetic diversity and molecular epidemiology of C. tropicalis from different parts of the world. However, the global pattern of genetic variation remains largely unknown. Here we analyzed the published multilocus sequence data at six loci for 876 isolates from 16 countries representing five continents. Our results showed that 280 of the 2677 (10.5%) analyzed nucleotides were polymorphic, resulting in a mean of 82 (a range of 38–150) genotypes per locus and a total of 633 combined diploid sequence types (DSTs). Among these, 93 combined DSTs were shared by 336 strains, including 10 by strains from different continents. Analysis of Molecular Variance (AMOVA) showed that 89% of the observed genetic variations were found within regional and national populations while < 10% was due to among-country separations. Pairwise geographic population analyses showed overall low but statistically significant genetic differentiation between most geographic populations, with the Singaporean and Indian populations being the most distinct from other populations. However, the Mantel test showed no significant correlation between genetic distance and geographic distance among the geographic populations. Consistent with high genetic variation within and limited variations among geographic populations, results from STRUCTURE analyses showed that the 876 isolates could be grouped into 15 genetic clusters, with each cluster having a broad geographic distribution. Together, our results suggest frequent gene flows among certain regional, national, and continental populations of C. tropicalis, resulting in abundant regional and national genetic diversities of this important human fungal pathogen.
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Affiliation(s)
- Jin-Yan Wu
- Public Research Laboratory, Hainan Medical University, Haikou, China.,Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Duan-Yong Zhou
- Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Ying Zhang
- Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Fei Mi
- Research Institute of Nutrition and Food Science, Kunming Medical University, Kunming, China
| | - Jianping Xu
- Public Research Laboratory, Hainan Medical University, Haikou, China.,Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China.,Department of Biology, McMaster University, Hamilton, ON, Canada
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15
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Candida tropicalis geographic population structure maintenance and dispersion in the coastal environment may be influenced by the climatic season and anthropogenic action. Microb Pathog 2018; 128:63-68. [PMID: 30550843 DOI: 10.1016/j.micpath.2018.12.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 12/10/2018] [Accepted: 12/11/2018] [Indexed: 11/24/2022]
Abstract
Candida tropicalis is a pathogenic yeast with worldwide recognition as the second or third more frequently isolated species in Latin America, for both superficial and systemic infections. Because of its high prevalence, and growing clinical interest, it is essential to understand genetic variability patterns of this important Candida species in the tropics. Besides belonging to the human normal microbiota, C. tropicalis may be found in other warm blood animals and in the environment, including water and sand of beaches. The aims of the present study were to evaluate genotypic and phenotypic variability of 62 isolates of C. tropicalis obtained from the coastal environment in Northeast Brazil using microsatellite and MALDI-TOF/MS comparisons. There was a relatively low correspondence between these typing techniques employed. Therefore, further studies are needed to consolidate the use of MALDI-TOF/MS as a yeast typing tool. Nevertheless, the two methods employed demonstrated the heterogeneity of C. tropicalis in a coastal environment. We also found relative maintenance of the population structure within the same season, which may reinforce the idea that this species presents the potential to remain in the environment for a long period of time. In addition, highly related strains were found within different geographic points of collection, demonstrating that this strain may be dispersed at long distances, probably influenced by anthropogenic actions and driven by the sea tides and wind.
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16
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Multilocus sequence typing of Candida albicans isolates from the oral cavities of patients undergoing haemodialysis. Sci Rep 2018; 8:16413. [PMID: 30401875 PMCID: PMC6219599 DOI: 10.1038/s41598-018-34565-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 10/17/2018] [Indexed: 12/15/2022] Open
Abstract
This study evaluates the prevalence, diversity, and genetic profiles of Candida albicans isolates recovered from the oral cavities of haemodialysis patients. Oral swab samples were obtained from haemodialysis patients (n = 126) and healthy control subjects (n = 233) and Candida species were characterised. There was no significant difference between the haemodialysis and control groups in the prevalence of yeast carriers (23.6% vs. 31.0%, respectively) or C. albicans carriers (19.8% vs. 21.0%, respectively). C. albicans was the most populous species in both cohorts, followed by C. parapsilosis. C. parapsilosis and C. glabrata were more prevalent in the haemodialysis group than in the control group (C. parapsilosis 5.6% vs. 0.9% and C. glabrata 3.2% vs. 0.4%, respectively; P < 0.05). C. albicans isolates were analysed by multilocus sequence typing and the results were used to construct a phylogenetic tree. Most haemodialysis isolates were placed into Clade 4 (20.0%) and Clade 19 (16.0%) and most control isolates into Clade 8 (17%) and Clade 4 (14.9%). Differences in the strain abundance in each clade were not statistically significant between the two groups. Moreover, there was no significant association between the health status or diagnosis and either the sequence types or clades.
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17
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Scordino F, Giuffrè L, Barberi G, Marino Merlo F, Orlando MG, Giosa D, Romeo O. Multilocus Sequence Typing Reveals a New Cluster of Closely Related Candida tropicalis Genotypes in Italian Patients With Neurological Disorders. Front Microbiol 2018; 9:679. [PMID: 29696003 PMCID: PMC5904457 DOI: 10.3389/fmicb.2018.00679] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/22/2018] [Indexed: 01/12/2023] Open
Abstract
Candida tropicalis is a pathogenic yeast that has emerged as an important cause of candidemia especially in elderly patients with hematological malignancies. Infections caused by this species are mainly reported from Latin America and Asian-Pacific countries although recent epidemiological data revealed that C. tropicalis accounts for 6-16.4% of the Candida bloodstream infections (BSIs) in Italy by representing a relevant issue especially for patients receiving long-term hospital care. The aim of this study was to describe the genetic diversity of C. tropicalis isolates contaminating the hands of healthcare workers (HCWs) and hospital environments and/or associated with BSIs occurring in patients with different neurological disorders and without hematological disease. A total of 28 C. tropicalis isolates were genotyped using multilocus sequence typing analysis of six housekeeping (ICL1, MDR1, SAPT2, SAPT4, XYR1, and ZWF1) genes and data revealed the presence of only eight diploid sequence types (DSTs) of which 6 (75%) were completely new. Four eBURST clonal complexes (CC2, CC10, CC11, and CC33) contained all DSTs found in this study and the CC33 resulted in an exclusive, well-defined, clonal cluster from Italy. In conclusion, C. tropicalis could represent an important cause of BSIs in long-term hospitalized patients with no underlying hematological disease. The findings of this study also suggest a potential horizontal transmission of a specific C. tropicalis clone through hands of HCWs and expand our understanding of the molecular epidemiology of this pathogen whose population structure is still far from being fully elucidated as its complexity increases as different categories of patients and geographic areas are examined.
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Affiliation(s)
- Fabio Scordino
- Scientific Institute for Research, Hospitalization and Health Care (IRCCS), Centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | - Letterio Giuffrè
- Department of Veterinary Sciences, Division of Animal Production, University of Messina, Messina, Italy
| | - Giuseppina Barberi
- Scientific Institute for Research, Hospitalization and Health Care (IRCCS), Centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | - Francesca Marino Merlo
- Scientific Institute for Research, Hospitalization and Health Care (IRCCS), Centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | - Maria Grazia Orlando
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Domenico Giosa
- Scientific Institute for Research, Hospitalization and Health Care (IRCCS), Centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | - Orazio Romeo
- Scientific Institute for Research, Hospitalization and Health Care (IRCCS), Centro Neurolesi "Bonino-Pulejo", Messina, Italy.,Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
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18
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Development of Echinocandin Resistance in Candida tropicalis following Short-Term Exposure to Caspofungin for Empiric Therapy. Antimicrob Agents Chemother 2018; 62:AAC.01926-17. [PMID: 29437623 DOI: 10.1128/aac.01926-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 01/22/2018] [Indexed: 12/16/2022] Open
Abstract
Isolation of two echinocandin-resistant Candida tropicalis strains from endotracheal secretions of a patient following short-term exposure to caspofungin is described. Both strains exhibited resistance to echinocandins by Etest and reference broth microdilution, showing a homozygous S645P mutation within the hot spot 1 (HS-1) region of FKS1 and belonging to a unique multilocus sequence type. Other C. tropicalis isolates collected from patients in the same intensive care unit within a 60-day period were susceptible to echinocandins and contained wild-type FKS1 sequences.
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19
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Al-Obaid K, Asadzadeh M, Ahmad S, Khan Z. Population structure and molecular genetic characterization of clinical Candida tropicalis isolates from a tertiary-care hospital in Kuwait reveal infections with unique strains. PLoS One 2017; 12:e0182292. [PMID: 28854190 PMCID: PMC5576731 DOI: 10.1371/journal.pone.0182292] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/15/2017] [Indexed: 11/19/2022] Open
Abstract
Candida tropicalis is a frequently isolated yeast species causing bloodstream, urinary tract and other infections particularly in patients admitted to intensive care units (ICUs) and those requiring prolonged urinary catheterization (UC) or receiving broad-spectrum antibiotics (BSA). This study investigated clinical characteristics and genetic relatedness among C. tropicalis strains isolated from patients at Al-Amiri Hospital in Kuwait. C. tropicalis strains (n = 63) isolated from blood, genito-urinary, respiratory (RT) and digestive (GIT) tracts and wound sites from 54 patients were used. All isolates were phenotypically identified and tested against six antifungal drugs by using Vitek 2 system. Molecular identification was performed by PCR amplification of rDNA. Fingerprinting was achieved by 6-loci-based multilocus sequence typing (MLST) and data were analyzed by BioNumerics software for phylogenetic relationships. Patients mean age was >65 years and >20% patients were hospitalized in ICUs. Most patients had underlying conditions that included UC, BSA, diabetes and RT/GIT abnormalities. Most candiduria cases had UC, ureteric stent or suprapubic catheters. All isolates were identified as C. tropicalis by Vitek 2 and by species-specific PCR. Sixty-two isolates were susceptible to all tested antifungal drugs. MLST identified 59 diploid sequence types (DSTs) including 54 newly-identified DSTs. C. tropicalis isolates from multiple sites of same patient usually belonged to different DSTs. Interestingly, 56 of 57 isolates from 48 patients belonged to unique genotypes. Only six isolates from six patients belonged to three DSTs (clusters), however, C. tropicalis strains in each cluster were isolated >3 months apart. Our data show diverse origins of C. tropicalis infections in Kuwait as most isolates were unique strains. There was no obvious correlation between cluster isolates with time of isolation and/or hospital ward of their origin. This study presents the first MLST analysis of C. tropicalis isolates from Middle East and may be useful for studying genetic relationships among global C. tropicalis strains.
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Affiliation(s)
- Khaled Al-Obaid
- Microbiology, Department of Medical Laboratories, Al-Amiri Hospital, Sharq, Kuwait
| | - Mohammad Asadzadeh
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
- * E-mail:
| | - Ziauddin Khan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
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