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McTaggart LR, Eshaghi A, Hota S, Poutanen SM, Johnstone J, De Luca DG, Bharat A, Patel SN, Kus JV. First Canadian report of transmission of fluconazole-resistant Candida parapsilosis within two hospital networks confirmed by genomic analysis. J Clin Microbiol 2024; 62:e0116123. [PMID: 38112529 PMCID: PMC10793253 DOI: 10.1128/jcm.01161-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/06/2023] [Indexed: 12/21/2023] Open
Abstract
Candida parapsilosis is a common cause of non-albicans candidemia. It can be transmitted in healthcare settings resulting in serious healthcare-associated infections and can develop drug resistance to commonly used antifungal agents. Following a significant increase in the percentage of fluconazole (FLU)-nonsusceptible isolates from sterile site specimens of patients in two Ontario acute care hospital networks, we used whole genome sequence (WGS) analysis to retrospectively investigate the genetic relatedness of isolates and to assess potential in-hospital spread. Phylogenomic analysis was conducted on all 19 FLU-resistant and seven susceptible-dose dependent (SDD) isolates from the two hospital networks, as well as 13 FLU susceptible C. parapsilosis isolates from the same facilities and 20 isolates from patients not related to the investigation. Twenty-five of 26 FLU-nonsusceptible isolates (resistant or SDD) and two susceptible isolates from the two hospital networks formed a phylogenomic cluster that was highly similar genetically and distinct from other isolates. The results suggest the presence of a persistent strain of FLU-nonsusceptible C. parapsilosis causing infections over a 5.5-year period. Results from WGS were largely comparable to microsatellite typing. Twenty-seven of 28 cluster isolates had a K143R substitution in lanosterol 14-α-demethylase (ERG11) associated with azole resistance. As the first report of a healthcare-associated outbreak of FLU-nonsusceptible C. parapsilosis in Canada, this study underscores the importance of monitoring local antimicrobial resistance trends and demonstrates the value of WGS analysis to detect and characterize clusters and outbreaks. Timely access to genomic epidemiological information can inform targeted infection control measures.
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Affiliation(s)
| | | | - Susy Hota
- Infection Prevention and Control Department, University Health Network, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Susan M. Poutanen
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Microbiology, University Health Network/Sinai Health, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Jennie Johnstone
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Infection Prevention and Control Department, Sinai Health, Toronto, Ontario, Canada
| | - Domenica G. De Luca
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Amrita Bharat
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Samir N. Patel
- Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Julianne V. Kus
- Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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2
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Wang T, Lu Y, Wu J, Yu B. Composition and dynamics of intestinal fungi during the postnatal 2 months of very low birth weight infants. Eur J Pediatr 2024; 183:403-414. [PMID: 37906308 PMCID: PMC10857973 DOI: 10.1007/s00431-023-05257-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 11/02/2023]
Abstract
It has been found that intestinal fungi play a role in the composition of the intestinal microecology and in the formation and development of the immunity during childhood. We investigated the gut fungi composition of preterm infants to analysis composition and dynamics of intestinal fungi during the postnatal 2 months of very low birth weight infants. We collected feces from 34 very low birth weight infants (VLBWI) and 28 preterm infants with birth weight >1500 g. We extracted total fungal DNA from feces and analyzed the composition of gut fungus through ITS sequencing. The fungal detectable rate in the experimental group peaked on day 3 (85.19%), then gradually decreased and started to show an increasing trend again by day 28. There were significant differences in the alpha diversity of intestinal fungus between VLBWI and controls, and the VLBWI had its own characteristics at different time points in richness and diversity. A total of 10 phylums and 342 genera were identified in all VLBWI samples. The dominant fungal phylum of the VLBWI group is Ascomycota (50.3%)and Basidiomycota (48.8%). The functional metabolic activity of the experimental group was lower than that of the control group. CONCLUSION The composition and abundance of VLBWI intestinal fungal showed several alterations during the first 2 months of life. The prediction of gut microbiota function suggests that intestinal metabolic function may be altered in VLBWI. WHAT IS KNOWN • A limited number of studies has been found that symbiont fungi may be able to calibrate host immunological responses, promote development of peripheral lymphoid organs, promote T cell responses, and even may be associated with the development of certain diseases, such as inflammatory bowel disease (IBD), NEC, and allergic diseases. However, previous studies on intestinal microecology have mainly focused on adults while neglecting the role of fungi in the gut of children due to the much lower abundance of intestinal fungi than bacteria, limitations of techniques for detecting fungi, the difficulty of obtaining samples, and the absence of largescale reference databases. WHAT IS NEW • In recent years, the discovery and development of fungal detection technologies such as 18s rDNA sequencing technology, Internal Transcribed Spacer(ITS), and DNA fingerprinting technology have further broadened the perspective on the impact of intestinal fungal exposure in early life.
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Affiliation(s)
- Ting Wang
- Health Science Center, Ningbo University, Ningbo, Zhejiang, China
| | - Yanbo Lu
- Pediatrics, Ningbo Women and Children's Hospital, Ningbo, Zhejiang, China
| | - Junhua Wu
- Pediatrics, Ningbo Women and Children's Hospital, Ningbo, Zhejiang, China.
| | - Beirong Yu
- Pediatrics, Ningbo Women and Children's Hospital, Ningbo, Zhejiang, China
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3
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Azevedo MJ, Araujo R, Campos J, Campos C, Ferreira AF, Falcão-Pires I, Ramalho C, Zaura E, Pinto E, Sampaio-Maia B. Vertical Transmission and Antifungal Susceptibility Profile of Yeast Isolates from the Oral Cavity, Gut, and Breastmilk of Mother-Child Pairs in Early Life. Int J Mol Sci 2023; 24:ijms24021449. [PMID: 36674962 PMCID: PMC9867488 DOI: 10.3390/ijms24021449] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/13/2023] Open
Abstract
Yeast acquisition begins at birth; however, the contribution of the mother on yeast transmission to the offspring and associated resistance is yet to be clarified. The aim of this study was to explore the vertical transmission of yeasts and their antifungal susceptibility profile in early life. Oral, fecal, and breastmilk samples were collected from 73 mother-child pairs four to twelve weeks after delivery and cultured on Sabouraud dextrose agar with chloramphenicol. The isolates were identified by MALDI-TOF MS. The vertical transmission was studied by microsatellite genotyping. Antifungal susceptibility was determined for fluconazole, voriconazole, miconazole, anidulafungin, and nystatin by broth microdilution assay, following CLSI-M60 guidelines. A total of 129 isolates were identified from 53% mother-child pairs. We verified the vertical transmission of Candida albicans (n = three mother-child pairs) and Candida parapsilosis (n = one mother-child pair) strains, including an antifungal resistant strain transmitted from breastmilk to the gut of a child. Most isolates were susceptible to the tested antifungals, with the exception of four C. albicans isolates and one R. mucilaginosa isolate. The vertical transmission of yeasts happens in early life. This is the first work that demonstrated the role of the mother as a source of transmission of antifungal-resistant yeasts to the child.
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Affiliation(s)
- Maria João Azevedo
- INEB—Instituto Nacional de Engenharia Biomédica, 4150-177 Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- Department of Preventive Dentistry, Academic Center for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, 1081 LA Amsterdam, The Netherlands
| | - Ricardo Araujo
- INEB—Instituto Nacional de Engenharia Biomédica, 4150-177 Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Campos
- INEB—Instituto Nacional de Engenharia Biomédica, 4150-177 Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Carla Campos
- Serviço de Patologia Clínica, Departamento de Patologia e Medicina Laboratorial, Instituto Português de Oncologia do Porto Francisco Gentil, 4200-072 Porto, Portugal
- Escola Superior de Saúde, Instituto Politécnico do Porto, 4200-072 Porto, Portugal
| | | | - Inês Falcão-Pires
- Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal
| | - Carla Ramalho
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal
- Department of Gynecology and Obstetrics, Centro Hospitalar Universitário de São João, 4200-319 Porto, Portugal
| | - Egija Zaura
- Department of Preventive Dentistry, Academic Center for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, 1081 LA Amsterdam, The Netherlands
| | - Eugénia Pinto
- Faculdade de Farmácia, Universidade do Porto, 4050-313 Porto, Portugal
- Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto, 4450-208 Matosinhos, Portugal
| | - Benedita Sampaio-Maia
- INEB—Instituto Nacional de Engenharia Biomédica, 4150-177 Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- Faculdade de Medicina Dentária, Universidade do Porto, 4200-393 Porto, Portugal
- Correspondence:
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4
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James SA, Phillips S, Telatin A, Baker D, Ansorge R, Clarke P, Hall LJ, Carding SR. Preterm Infants Harbour a Rapidly Changing Mycobiota That Includes Candida Pathobionts. J Fungi (Basel) 2020; 6:E273. [PMID: 33182444 PMCID: PMC7712117 DOI: 10.3390/jof6040273] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 12/22/2022] Open
Abstract
Fungi and the mycobiome are a fundamental part of the human microbiome that contributes to human health and development. Despite this, relatively little is known about the mycobiome of the preterm infant gut. Here, we have characterised faecal fungal communities present in 11 premature infants born with differing degrees of prematurity and mapped how the mycobiome develops during early infancy. Using an ITS1 sequencing-based approach, the preterm infant gut mycobiome was found to be often dominated by a single species, typically a yeast. Candida was the most abundant genus, with the pathobionts C.albicans and C.parapsilosis highly prevalent and persistent in these infants. Gestational maturity at birth affected the distribution and abundance of these Candida, with hospital-associated C.parapsilosis more prevalent and abundant in infants born at less than 31 weeks. Fungal diversity was lowest at 6 months, but increased with age and change of diet, with food-associated Saccharomycescerevisiae most abundant in infants post weaning. This study provides a first insight into the fungal communities present within the preterm infant gut, identifying distinctive features including the prominence of pathobiont species, and the influence age and environmental factors play in shaping the development of the mycobiome.
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Affiliation(s)
- Stephen A. James
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
| | - Sarah Phillips
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
| | - Andrea Telatin
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
| | - David Baker
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
| | - Rebecca Ansorge
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
| | - Paul Clarke
- Neonatal Intensive Care Unit, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich NR4 7UY, UK;
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK
| | - Lindsay J. Hall
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
- Ziel—Institute for Food and Health, Technical University of Munich, 85354 Freising, Germany
| | - Simon R. Carding
- Gut Microbes and Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; (S.A.J.); (S.P.); (A.T.); (D.B.); (R.A.)
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK
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5
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Zhang L, Yu SY, Chen SCA, Xiao M, Kong F, Wang H, Ning YT, Lu MY, Sun TS, Hou X, Zhou ML, Kang W, Zhang G, Duan SM, Xu YC. Molecular Characterization of Candida parapsilosis by Microsatellite Typing and Emergence of Clonal Antifungal Drug Resistant Strains in a Multicenter Surveillance in China. Front Microbiol 2020; 11:1320. [PMID: 32612597 PMCID: PMC7309193 DOI: 10.3389/fmicb.2020.01320] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 05/25/2020] [Indexed: 12/22/2022] Open
Abstract
Candida parapsilosis is an important species causing invasive candidiasis (IC) in China. The present survey was a national multicenter study of the molecular epidemiology and antifungal susceptibility profiles of C. parapsilosis. Non-duplicate C. parapsilosis isolates were collected from 10 hospitals across China in the CHIF-NET program 2016–2017. Isolates were genotyped using four highly polymorphic microsatellite markers, and susceptibility profiles determined using Sensititre YeastOneTM YO10. A total of 319 C. parapsilosis from separate patients with IC were studied; 49.2, 17.9, and 10.3% isolates were from patients in surgical departments, general intensive care units (ICUs) and neonatal ICUs (NICU), respectively. C. parapsilosis showed good susceptibility to nine antifungal drugs. Microsatellite analysis identified 122 microsatellite (MT) types. Most MT types had sporadic distribution. However, we identified 32 clusters across 10 hospitals; seven clusters were caused by seven endemic genotypes involving five or more isolates in hospitals designated as H01, H02, H06, and H10. These clusters mainly affected surgical departments and ICUs, except for genotype MT42 which was seen in 22 patients from NICU (hospital H06). Of 16 fluconazole-resistant isolates, seven from hospital H02 shared the same genotype MT70, and three from hospital H04 were of genotype MT47. For 37 isolates with non-wild type MICs to 5-flucytosine, 29 were from hospital H01 (genotype MT48). Here we present the first nationwide molecular epidemiology study of C. parapsilosis in China, identified several previously unrecognized clusters, which included antifungal drug resistant isolates. These findings provide important data for control of IC in China.
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Affiliation(s)
- Li Zhang
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Shu-Ying Yu
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Sharon C-A Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR - Pathology West, University of Sydney, Westmead, NSW, Australia
| | - Meng Xiao
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Fanrong Kong
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR - Pathology West, University of Sydney, Westmead, NSW, Australia
| | - He Wang
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Ya-Ting Ning
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Min-Ya Lu
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Tian-Shu Sun
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China.,Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xin Hou
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Meng-Lan Zhou
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Wei Kang
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Ge Zhang
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Si-Meng Duan
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Ying-Chun Xu
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
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6
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Magobo RE, Lockhart SR, Govender NP. Fluconazole-resistant Candida parapsilosis strains with a Y132F substitution in the ERG11 gene causing invasive infections in a neonatal unit, South Africa. Mycoses 2020; 63:471-477. [PMID: 32124485 DOI: 10.1111/myc.13070] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/23/2020] [Indexed: 12/20/2022]
Abstract
INTRODUCTION The prevalence of azole resistance in C parapsilosis is very low in most parts of the world. However, South Africa has reported an exceptionally high prevalence of azole resistance in C parapsilosis strains isolated from candidaemia cases. We aimed to determine the possible molecular mechanisms of fluconazole resistance in C parapsilosis isolates obtained through surveillance at a large neonatal unit at a South African academic hospital. METHODS We sequenced the ERG11 and MRR1 genes of C parapsilosis isolates recovered from cases of neonatal candidemia, followed by microsatellite genotyping. A total of 73 isolates with antifungal susceptibility results were analysed. RESULTS Of these, 57 (78%) were resistant, 11 (15%) susceptible dose-dependent and 5 (7%) susceptible. The most commonly identified amino acid substitution within the ERG11 gene was Y132F in 68% (39/57) of fluconazole-resistant isolates and none in susceptible isolates. Three amino acid substitutions (R405K, G583R and A619V) and 1 nucleotide deletion at position 1331 were identified within MRR1 gene in 19 (26%) isolates. Microsatellite genotyping grouped isolates into four clusters (50 isolates). Cluster 1 accounted for 23% (17/73) of all cases, cluster 2 for 22% (16/73), cluster 3 for 14% (10/73) and cluster 4 for 10% (7/73). We found an association between cluster type and fluconazole resistance (P-value = .004). Isolates harbouring the Y132F substitution were more likely to belong to a cluster than non-Y132F isolates. CONCLUSION Fluconazole resistance in C parapsilosis strains from a single South African neonatal unit was associated with cluster type and predominantly driven by Y123F amino acid substitutions in the ERG11 gene.
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Affiliation(s)
- Rindidzani E Magobo
- Centre for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, A Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Nelesh P Govender
- Centre for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, A Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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7
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Magobo R, Mhlanga M, Corcoran C, Govender NP. Multilocus sequence typing of azole-resistant Candida auris strains, South Africa. S Afr J Infect Dis 2020; 35:116. [PMID: 34485470 PMCID: PMC8378186 DOI: 10.4102/sajid.v35i1.116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 01/16/2020] [Indexed: 11/25/2022] Open
Abstract
Background Candida auris is an emerging multidrug-resistant fungal pathogen associated with high mortality. Methods We investigated the genetic relatedness of clinical C. auris isolates from patients admitted to either public- or private-sector hospitals, which were submitted to a reference laboratory from 2012 to 2015. Patient demographics and clinical details were recorded. We performed antifungal susceptibility testing, sequencing of the hotspot 1 and 2 regions of the FKS1 and FKS2 genes for all isolates with an echinocandin minimum inhibitory concentration (MIC) of ≥1 µg/mL and cluster analysis using multilocus sequence typing. Results Eighty-five isolates were confirmed as C. auris. The median patient age was 59 years [inter-quartile range (IQR): 48–68 years], with male patients accounting for 68% of cases. Specimen types included urine (29%), blood (27%), central venous catheter tips (25%), irrigation fluid (7%), tissue (5%), respiratory tract specimens (4%) and other (3%). Ninety-seven per cent of isolates were resistant to fluconazole, 7% were resistant to both fluconazole and voriconazole, 8% were resistant to both fluconazole and echinocandins (considered multidrug resistant) and all were susceptible to amphotericin B. Of the 15 randomly selected fluconazole-resistant isolates, 14 isolates had an isavuconazole MIC ≤ 1 µg/mL. No FKS mutations were detected. Multilocus sequence typing (MLST) analysis grouped isolates into two clusters: cluster 1 and cluster 2 comprising 83 and 2 isolates, respectively. Conclusions Azole-resistant C. auris strains circulating in South African hospitals were related by MLST, but the possibility of nosocomial transmission should be explored using a more discriminatory technique, for example, whole genome sequencing.
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Affiliation(s)
- Rindidzani Magobo
- Centre for Healthcare-associated Infections, Antimicrobial Resistance and Mycoses, Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg, South Africa.,Ampath National Reference Laboratory, Pretoria, South Africa
| | - Mabatho Mhlanga
- Centre for Healthcare-associated Infections, Antimicrobial Resistance and Mycoses, Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Craig Corcoran
- Ampath National Reference Laboratory, Pretoria, South Africa
| | - Nelesh P Govender
- Centre for Healthcare-associated Infections, Antimicrobial Resistance and Mycoses, Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg, South Africa
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8
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Identification of Candida Species from Clinical Samples in a Honduran Tertiary Hospital. Pathogens 2019; 8:pathogens8040237. [PMID: 31731617 PMCID: PMC6963973 DOI: 10.3390/pathogens8040237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/25/2019] [Accepted: 10/27/2019] [Indexed: 12/15/2022] Open
Abstract
Candida species are one of the most important causes of human infections, especially in hospitals and among immunocompromised patients. The correct and rapid etiological identification of yeast infections is important to provide adequate therapy, reduce mortality, and control outbreaks. In this study, Candida species were identified in patients with suspected fungal infection, and phenotypic and genotypic identification methods were compared. A total of 167 axenic fungal cultures and 46 clinical samples were analyzed by HardyCHROM®, MicroScan®(Omron Microscan Systems Inc, Renton, WA, USA), and PCR-RFLP (Restriction Fragment Length Polymorphisms). The species of the C. albicans complex were the most frequent, followed by C. tropicalis and C. glabrata. Less common but clinically relevant species of Candida were also isolated. The comparison between the three methods was concordant, especially for the most common Candida species. Fungal DNA amplification was successful in all clinical samples.
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9
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Asadzadeh M, Ahmad S, Al-Sweih N, Hagen F, Meis JF, Khan Z. High-resolution fingerprinting of Candida parapsilosis isolates suggests persistence and transmission of infections among neonatal intensive care unit patients in Kuwait. Sci Rep 2019; 9:1340. [PMID: 30718894 PMCID: PMC6361955 DOI: 10.1038/s41598-018-37855-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/07/2018] [Indexed: 12/29/2022] Open
Abstract
Candida parapsilosis causes ~35% of all candidemia cases in neonates. High-resolution fingerprinting of C. parapsilosis isolates from neonatal intensive care unit (NICU) patients in Maternity Hospital (MH) was performed to identify epidemiologically related strains. Sixty-eight bloodstream/colonizing strains isolated from 59 NICU patients, two isolates from health care workers (HCWs) from MH and 18 bloodstream isolates from two other hospitals were used. Six microsatellite markers were employed, isolates were assigned a numerical microsatellite genotype (MSG), dendrogram was constructed and similarities between genotypes were visualized by minimum spanning tree. Fifty bloodstream isolates from MH yielded 37 MSGs with 20 isolates clustering in 7 MSGs. Duplicate isolates and colonizing strains yielded same/highly similar MSG as bloodstream isolates. Colonizing strains from two non-candidemia patients yielded unique MSGs while others belonged to a cluster. All isolates from HCWs and from two other hospitals belonged to unique MSGs. Cluster isolates came from patients in NICU-1 or from neonates in NICU-1 and other NICUs. Clonal complexes comprising closely related genotypes indicative of microevolution were also detected. Our data show that some C. parapsilosis strains have persisted in MH environment over several years and these endemic genotypes were transmitted to other patients in NICU-1 and/or other nearby NICUs.
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Affiliation(s)
- Mohammad Asadzadeh
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Noura Al-Sweih
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Ferry Hagen
- Department of Medical Mycology, Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands.,Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital (CWZ), Nijmegen, Netherlands
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital (CWZ), Nijmegen, Netherlands.,Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, Netherlands
| | - Ziauddin Khan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait.
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10
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Trobajo-Sanmartín C, Ezpeleta G, Pais C, Eraso E, Quindós G. Design and validation of a multiplex PCR protocol for microsatellite typing of Candida parapsilosis sensu stricto isolates. BMC Genomics 2018; 19:718. [PMID: 30268088 PMCID: PMC6162959 DOI: 10.1186/s12864-018-5065-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 09/11/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Analysis of polymorphic microsatellite markers (STR) is a helpful genotyping technique to differentiate Candida parapsilosis sensu stricto isolates. The aim of this study is to develop and perform an initial validation of an alternative protocol for the reliable and accurate microsatellite genotyping of C. parapsilosis sensu stricto isolates using high-throughput multiplex PCR. To achieve this, the results obtained using the new protocol were compared to the ones obtained using a previously described reference method. To that end, diagnostic accuracy, informativeness and discrimination parameters were estimated. RESULTS Our results showed good concordance between both methods (Kappa index: 0.920), leading to a high sensitivity (1; CI(95%) (0.991-1)) and specificity (1; CI(95%) (0.772-1)) after the validation of the new protocol. Moreover, the electropherograms profiles obtained with the new PCR scheme showed a high signal to noise ratio (SNR). CONCLUSIONS The new multiplex protocol is valuable for the differentiation of C. parapsilosis sensu stricto, with direct clinical applications. Besides, the new protocol represents a shortening the hands-on time, reducing the sample manipulation (dismissing the possibility of cross-contamination), maintaining the quality of the results (when compared to the ones obtained with the reference method), and helping to the standardization and simplification of the genotyping scheme.
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Affiliation(s)
- Camino Trobajo-Sanmartín
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, UFI11/25 (Microbios y Salud), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Apartado 699, E-48080 Bilbao, Spain
| | - Guillermo Ezpeleta
- Departamento de Medicina Preventiva y Salud Pública, Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Bilbao, Spain
- Servicio de Medicina Preventiva e Higiene Hospitalaria, Complejo Hospitalario de Navarra, Pamplona, Spain
| | - Célia Pais
- Centro de Biologia Molecular e Ambiental (CBMA), Departamento de Biologia, Universidade do Minho, Braga, Portugal
| | - Elena Eraso
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, UFI11/25 (Microbios y Salud), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Apartado 699, E-48080 Bilbao, Spain
| | - Guillermo Quindós
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, UFI11/25 (Microbios y Salud), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Apartado 699, E-48080 Bilbao, Spain
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11
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Neji S, Hadrich I, Ilahi A, Trabelsi H, Chelly H, Mahfoudh N, Cheikhrouhou F, Sellami H, Makni F, Ayadi A. Molecular Genotyping of Candida parapsilosis Species Complex. Mycopathologia 2018; 183:765-775. [DOI: 10.1007/s11046-018-0278-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/10/2017] [Indexed: 11/30/2022]
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12
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Genetic Diversity and Antifungal Susceptibility of Candida parapsilosis Sensu Stricto Isolated from Bloodstream Infections in Turkish Patients. Mycopathologia 2018; 183:701-708. [PMID: 29725811 DOI: 10.1007/s11046-018-0261-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 04/16/2018] [Indexed: 10/17/2022]
Abstract
Candida parapsilosis sensu stricto is an emerging cause of hospital-acquired Candida infections, predominantly in southern Europe, South America, and Asia. We investigated the genetic diversity and antifungal susceptibility profile of 170 independent C. parapsilosis sensu stricto strains obtained from patients with candidemia who were treated at the Ege University Hospital in Izmir, Turkey, between 2006 and 2014. The identity of each strain was confirmed via PCR amplification and digestion of the secondary alcohol dehydrogenase-encoding gene. The 24-h geometric mean minimum inhibitory concentrations of the antifungal agents, in increasing order, were as follows: posaconazole, 0.10 µg/mL; voriconazole, 0.21 µg/mL; caspofungin, 0.38 µg/mL; amphotericin B, 0.61 µg/mL; anidulafungin, 0.68 µg/mL; and fluconazole, 2.95 µg/mL. Microsatellite genotyping of the isolates (using fluorescently labeled primers and a panel of four different short-nucleotide repeat fragments) identified 25, 17, 17, and 8 different allelic genotypes at the CP6, B5, CP4, and CP1 locus, respectively. Posaconazole, caspofungin, and amphotericin B showed the greatest in vitro activity of the tested systemic azole, echinocandin, and polyene agents, respectively, and the observed antifungal susceptibility of the isolates was shown to be independent of their isolation source. We obtained a combined discriminatory power of 0.99 with a total of 130 genotypes for 170 isolates tested. Finally, microsatellite profiling analysis confirmed the presence of identical genotype between separate isolates, supporting that effective surveillance and infection-prevention programs are essential to limit the impact of C. parapsilosis sensu stricto on hospitalized patients' health.
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13
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Population Structure of Candida parapsilosis: No Genetic Difference Between French and Uruguayan Isolates Using Microsatellite Length Polymorphism. Mycopathologia 2017; 183:381-390. [PMID: 29147867 DOI: 10.1007/s11046-017-0224-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 11/06/2017] [Indexed: 12/19/2022]
Abstract
Candida parapsilosis is a human commensal yeast, frequently involved in infection worldwide and especially in neonates. It is the second species responsible for bloodstream infections in Uruguay and the third species in France. We were interested in knowing whether the population structure of isolates responsible for candidemia in France and in Uruguay was different. Genotyping methods based on microsatellite length polymorphism (MLP) have been described and are especially used for investigation of local outbreaks. We therefore determined the genotypes of 159 C. parapsilosis isolates recovered from 122 patients (84 French patients from 43 hospitals and 38 Uruguayan patients from 10 hospitals) using three microsatellites markers previously described. Our results confirmed that C. parapsilosis population has a high genetic diversity, clonal inheritance and that majority of patients were infected by a single isolate. But we described recurrent infections due to related or unrelated genotypes resulting from isolates harboring loss or gain of heterozygosity. We also described three cases of coinfections due to unrelated genotypes. We did not uncover geographic specificity but observed two linked genotypes that seem to be associated with voriconazole resistance. Finally, among eight isolates involved in grouped cases, the genotypes were similar in six cases supporting the hypothesis of inter-patient transmission. These results confirmed the usefulness of performing MLP genotyping analysis for grouped cases of C. parapsilosis isolates in order to reinforce preventive hygiene measures.
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14
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Investigating Clinical Issues by Genotyping of Medically Important Fungi: Why and How? Clin Microbiol Rev 2017; 30:671-707. [PMID: 28490578 DOI: 10.1128/cmr.00043-16] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genotyping studies of medically important fungi have addressed elucidation of outbreaks, nosocomial transmissions, infection routes, and genotype-phenotype correlations, of which secondary resistance has been most intensively investigated. Two methods have emerged because of their high discriminatory power and reproducibility: multilocus sequence typing (MLST) and microsatellite length polymorphism (MLP) using short tandem repeat (STR) markers. MLST relies on single-nucleotide polymorphisms within the coding regions of housekeeping genes. STR polymorphisms are based on the number of repeats of short DNA fragments, mostly outside coding regions, and thus are expected to be more polymorphic and more rapidly evolving than MLST markers. There is no consensus on a universal typing system. Either one or both of these approaches are now available for Candida spp., Aspergillus spp., Fusarium spp., Scedosporium spp., Cryptococcus neoformans, Pneumocystis jirovecii, and endemic mycoses. The choice of the method and the number of loci to be tested depend on the clinical question being addressed. Next-generation sequencing is becoming the most appropriate method for fungi with no MLP or MLST typing available. Whatever the molecular tool used, collection of clinical data (e.g., time of hospitalization and sharing of similar rooms) is mandatory for investigating outbreaks and nosocomial transmission.
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15
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Magobo RE, Naicker SD, Wadula J, Nchabeleng M, Coovadia Y, Hoosen A, Lockhart SR, Govender NP. Detection of neonatal unit clusters of Candida parapsilosis fungaemia by microsatellite genotyping: Results from laboratory-based sentinel surveillance, South Africa, 2009-2010. Mycoses 2017; 60:320-327. [PMID: 28101934 DOI: 10.1111/myc.12596] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/08/2016] [Accepted: 12/08/2016] [Indexed: 11/28/2022]
Abstract
Neonatal candidaemia is a common, deadly and costly hospital-associated disease. To determine the genetic diversity of Candida parapsilosis causing fungaemia in South African neonatal intensive care units (NICUs). From February 2009 through to August 2010, cases of candidaemia were reported through laboratory-based surveillance. C. parapsilosis isolates from neonatal cases were submitted for identification by internal transcribed spacer (ITS) region sequencing, antifungal susceptibility testing and microsatellite genotyping. Cluster analysis was performed using Unweighted Pair Group Method with Arithmetic Mean (UPGMA). Of 1671 cases with a viable Candida isolate, 393 (24%) occurred among neonates. Isolates from 143 neonatal cases were confirmed as C. parapsilosis sensu stricto. Many isolates were resistant to fluconazole (77/143; 54%) and voriconazole (20/143; 14%). Of 79 closely-related genotypes, 18 were represented by ≥2 isolates; 61 genotypes had a single isolate each. Seven clusters, comprised of 82 isolates, were identified at five hospitals in three provinces. Isolates belonging to certain clusters were significantly more likely to be fluconazole resistant: all cluster 7 isolates and the majority of cluster 4 (78%), 5 (89%) and 6 (67%) isolates (P<.001). Candida parapsilosis-associated candidaemia in public-sector NICUs was caused by closely related genotypes and there was molecular evidence of undetected outbreaks as well as intra-hospital transmission.
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Affiliation(s)
- Rindidzani E Magobo
- Division of the National Health Laboratory Service, National Institute for Communicable Diseases - Centre for Opportunistic, Tropical and Hospital Infections, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Serisha D Naicker
- Division of the National Health Laboratory Service, National Institute for Communicable Diseases - Centre for Opportunistic, Tropical and Hospital Infections, Johannesburg, South Africa
| | - Jeannette Wadula
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,National Health Laboratory Service, Chris Hani Baragwanath Hospital, Johannesburg, South Africa
| | - Maphoshane Nchabeleng
- National Health Laboratory Service, Dr George Mukhari Hospital, Medical University of South Africa, Ga-Rankuwa, South Africa
| | - Yacoob Coovadia
- National Health Laboratory Service, Inkosi Albert Luthuli Hospital, University of KwaZulu-Natal, Durban, South Africa
| | - Anwar Hoosen
- National Health Laboratory Service, Universitas Hospital, University of the Free State, Bloemfontein, South Africa
| | - Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Nelesh P Govender
- Division of the National Health Laboratory Service, National Institute for Communicable Diseases - Centre for Opportunistic, Tropical and Hospital Infections, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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16
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Wang H, Zhang L, Kudinha T, Kong F, Ma XJ, Chu YZ, Kang M, Sun ZY, Li RY, Liao K, Lu J, Zou GL, Xiao M, Fan X, Xu YC. Investigation of an unrecognized large-scale outbreak of Candida parapsilosis sensu stricto fungaemia in a tertiary-care hospital in China. Sci Rep 2016; 6:27099. [PMID: 27251023 PMCID: PMC4890031 DOI: 10.1038/srep27099] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/13/2016] [Indexed: 02/05/2023] Open
Abstract
A data analysis of yeast collections from the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) programme in 2013 revealed a sudden increase in the proportion of Candida parapsilosis complex isolates (n = 98) in one participating hospital (Hospital H). Out of 443 yeast isolates submitted to the CHIF-NET reference laboratory by Hospital H (2010–2014), 212 (47.9%) were identified as C. parapsilosis sensu stricto by sequencing analysis of the internal transcribed spacer region and D1/D2 domain of the 26S rRNA gene. Among the 212 C. parapsilosis sensu stricto isolates, 176 (83.0%) bloodstream-based isolates and 25 isolates from tip cultures of various vascular catheters from 25 patients with candidaemia, were subjected to microsatellite genotyping, and a phylogenetic relationship analysis was performed for 152 isolates. Among the 152 isolates, 45 genotypes (T01 to T45) were identified, and two prevalent genotypes (63.8%) were found: T15 (n = 74, 48.7%) and T16 (n = 23, 15.1%). These two main clones were confined mainly to three different wards of the hospital, and they persisted for 16–25 months and 12–13 months, respectively. The lack of proper coordination between the clinical microbiology laboratory and infection control staff as part of public health control resulted in the failure to timely identify an outbreak, which led to the wide and long-term dissemination of C. parapsilosis sensu stricto in Hospital H.
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Affiliation(s)
- He Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Li Zhang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Timothy Kudinha
- Charles Sturt University, Leeds Parade, Orange, New South Wales, Australia.,Centre for Infectious Diseases and Microbiology Laboratory Services, Westmead Hospital, Darcy Road, Westmead, New South Wales, Australia
| | - Fanrong Kong
- Centre for Infectious Diseases and Microbiology Laboratory Services, Westmead Hospital, Darcy Road, Westmead, New South Wales, Australia
| | - Xiao-Jun Ma
- Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yun-Zhuo Chu
- Department of Clinical Laboratory, the First Hospital of China Medical University, Shenyang, China
| | - Mei Kang
- Laboratory of Clinical Microbiology, West China Hospital, Sichuan University, Chengdu, China
| | - Zi-Yong Sun
- Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ruo-Yu Li
- Department of Clinical Laboratory, Peking University First Hospital, Beijing, China
| | - Kang Liao
- Department of Clinical Laboratory, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Juan Lu
- Department of Clinical Laboratory, the First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Gui-Ling Zou
- Department of Clinical Laboratory, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Meng Xiao
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xin Fan
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Ying-Chun Xu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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17
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Molecular mechanisms of fluconazole resistance in Candida parapsilosis isolates from a U.S. surveillance system. Antimicrob Agents Chemother 2014; 59:1030-7. [PMID: 25451046 DOI: 10.1128/aac.04613-14] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida parapsilosis is the second or third most common cause of candidemia in many countries. The Infectious Diseases Society of America recommends fluconazole as the primary therapy for C. parapsilosis candidemia. Although the rate of fluconazole resistance among C. parapsilosis isolates is low in most U.S. institutions, the resistance rate can be as high as 7.5%. This study was designed to assess the mechanisms of fluconazole resistance in 706 incident bloodstream isolates from U.S. hospitals. We sequenced the ERG11 and MRR1 genes of 122 C. parapsilosis isolates with resistant (30 isolates; 4.2%), susceptible dose-dependent (37 isolates; 5.2%), and susceptible (55 isolates) fluconazole MIC values and used real-time PCR of RNA from 17 isolates to investigate the regulation of MDR1. By comparing these isolates to fully fluconazole-susceptible isolates, we detected at least two mechanisms of fluconazole resistance: an amino acid substitution in the 14-α-demethylase gene ERG11 and overexpression of the efflux pump MDR1, possibly due to point mutations in the MRR1 transcription factor that regulates MDR1. The ERG11 single nucleotide polymorphism (SNP) was found in 57% of the fluconazole-resistant isolates and in no susceptible isolates. The MRR1 SNPs were more difficult to characterize, as not all resulted in overexpression of MDR1 and not all MDR1 overexpression was associated with an SNP in MRR1. Further work to characterize the MRR1 SNPs and search for overexpression of other efflux pumps is needed.
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18
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Microsatellite-based genotyping of Candida parapsilosis sensu stricto isolates reveals dominance and persistence of a particular epidemiological clone among neonatal intensive care unit patients. INFECTION GENETICS AND EVOLUTION 2012; 13:105-8. [PMID: 23022715 DOI: 10.1016/j.meegid.2012.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/13/2012] [Accepted: 09/14/2012] [Indexed: 11/20/2022]
Abstract
In this study, using multilocus microsatellite analysis, we report the genetic characterization of 27 Candida parapsilosis isolates recovered in two different periods of time (2007-2009 and 2011-2012) from infants hospitalized in the neonatal intensive care unit of a hospital in Messina, Italy. The results revealed the persistence and dominance of a particular infectious genotype among NICU patients and highlight the power of the used microsatellite markers in clarifying epidemiologic associations, detect micro-evolutionary variations and facilitating the recognition of outbreaks.
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