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Eades CP, Bakri ARBA, Lau JCY, Moore CB, Novak-Frazer L, Richardson MD, Rautemaa-Richardson R. Comparison of β-1-3-D-Glucan and Candida Mannan Biomarker Assays with Serological Tests for the Diagnosis of Candidemia. J Fungi (Basel) 2023; 9:813. [PMID: 37623584 PMCID: PMC10455369 DOI: 10.3390/jof9080813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023] Open
Abstract
Invasive candidiasis, including bloodstream infection (candidemia), encompasses the most severe forms of Candida infection. Several species-specific and non-specific serological assays are commercially available to aid in diagnosis. This study compared the performance of five such biomarker assays. Serum samples from 14 patients with proven or probable invasive candidiasis, and from 10 control patients, were included in the analysis. A total of 50 serum samples were tested using C. albicans germ tube antibody (CAGTA) assay (Vircell), C. albicans IgM, C. albicans IgG and Candida mannan assays (Dynamiker Biotechnology). Among these samples, the β-1-3-D-glucan (BDG) assay (Fungitell), a laboratory standard for the diagnosis of invasive candidiasis, was positive in 20 (40%), intermediate in five (10%) and negative in 25 (50%). In cases of proven or probable candidemia, the sensitivity and specificity of the BDG assay was 86% and 80%, respectively; the Candida mannan assay, 14% and 86%; the CAGTA test, 57% and 60%; the C. albicans IgM assay, 71% and 60%; and C. albicans IgG assay 29% and 90%. In 4/8 (50%) cases with multiple serum samples, C. albicans IgM was positive sooner than BDG. Thus, when used as a rule-out test for invasive candidiasis, our data suggest that the C. albicans IgM assay may assist antifungal stewardship (over serum BDG).
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Affiliation(s)
- Christopher P. Eades
- Department of Infectious Diseases, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK;
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Ahmed Rafezzan Bin Ahmed Bakri
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Jeffrey C. Y. Lau
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Caroline B. Moore
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Lilyann Novak-Frazer
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
- Mycology Reference Centre Manchester (MRCM), ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
| | - Malcolm D. Richardson
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
- Mycology Reference Centre Manchester (MRCM), ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
- Manchester Fungal Infection Group (MFIG), Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9NT, UK
| | - Riina Rautemaa-Richardson
- Department of Infectious Diseases, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK;
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
- Mycology Reference Centre Manchester (MRCM), ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
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Felix GN, de Freitas VLT, da Silva Junior AR, Magri MMC, Rossi F, Sejas ONE, Abdala E, Malbouisson LMS, Guimarães T, Benard G, Del Negro GMB. Performance of a Real-Time PCR Assay for the Detection of Five Candida Species in Blood Samples from ICU Patients at Risk of Candidemia. J Fungi (Basel) 2023; 9:635. [PMID: 37367571 DOI: 10.3390/jof9060635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 04/22/2023] [Accepted: 05/13/2023] [Indexed: 06/28/2023] Open
Abstract
The gold standard for diagnosing invasive candidiasis still relies on blood cultures, which are inefficient and time-consuming to analyze. We developed an in-house qPCR assay to identify the 5 major Candida species in 78 peripheral blood (PB) samples from ICU patients at risk of candidemia. Blood cultures and (1,3)-β-D-glucan (BDG) testing were performed concurrently to evaluate the performance of the qPCR. The qPCR was positive for DNA samples from all 20 patients with proven candidemia (positive PB cultures), showing complete concordance with Candida species identification in blood cultures, except for detection of dual candidemia in 4 patients, which was missed by blood cultures. Additionally, the qPCR detected Candida species in six DNA samples from patients with positive central venous catheters blood (CB) but negative PB cultures. BDG values were similarly high in these six samples and the ones with proven candidemia, strongly suggesting the diagnosis of a true candidemia episode despite the negative PB cultures. Samples from patients neither infected nor colonized yielded negative results in both the qPCR and BDG testing. Our qPCR assay was at least as sensitive as blood cultures, but with a shorter turnaround time. Furthermore, negative results from the qPCR provided strong evidence for the absence of candidemia caused by the five major Candida species.
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Affiliation(s)
- Gabriel N Felix
- Laboratory of Medical Mycology (LIM 53), Instituto de Medicina Tropical, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-000, Brazil
| | - Vera L T de Freitas
- Laboratório de Investigação Médica em Imunologia (LIM 48), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-000, Brazil
| | - Afonso R da Silva Junior
- Central Laboratory Division (LIM 03), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-010, Brazil
| | - Marcello M C Magri
- Central Laboratory Division (LIM 03), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-010, Brazil
- Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-010, Brazil
| | - Flavia Rossi
- Central Laboratory Division (LIM 03), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-010, Brazil
| | - Odeli N E Sejas
- Cancer Institute of São Paulo State (ICESP), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 01246-000, Brazil
| | - Edson Abdala
- Cancer Institute of São Paulo State (ICESP), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 01246-000, Brazil
| | - Luiz M S Malbouisson
- Discipline of Anesthesiology, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-010, Brazil
| | - Thais Guimarães
- Infectious Diseases Department, Hospital do Servidor Público Estadual de São Paulo (IAMSPE), São Paulo 04029-000, Brazil
| | - Gil Benard
- Laboratory of Medical Mycology (LIM 53), Instituto de Medicina Tropical, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-000, Brazil
| | - Gilda M B Del Negro
- Laboratory of Medical Mycology (LIM 53), Instituto de Medicina Tropical, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo 05403-000, Brazil
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Koc Ö, Kessler HH, Hoenigl M, Wagener J, Suerbaum S, Schubert S, Dichtl K. Performance of Multiplex PCR and β-1,3-D-Glucan Testing for the Diagnosis of Candidemia. J Fungi (Basel) 2022; 8:jof8090972. [PMID: 36135696 PMCID: PMC9504845 DOI: 10.3390/jof8090972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/05/2022] [Accepted: 09/15/2022] [Indexed: 11/28/2022] Open
Abstract
Bloodstream infections caused by Candida yeasts (candidemia) are associated with high morbidity and mortality. Diagnosis remains challenging, with the current gold standard—isolation from blood culture (BC)—being limited by low sensitivity and long turnaround time. This study evaluated the performance of two nonculture methods: PCR and β-1,3-D-glucan (BDG) testing. The sera of 103 patients with BC-proven candidemia and of 46 controls were analyzed with the Fungiplex Candida Real-Time PCR and the Wako β-Glucan Test. The BDG assay demonstrated higher sensitivity than the multiplex PCR (58% vs. 33%). This was particularly evident in ICU patients (60% vs. 28%) and in C. albicans candidemia (57% vs. 37%). The earlier prior to BC sampling the sera were obtained, the more the PCR sensitivity decreased (46% to 18% in the periods of 0−2 and 3−5 days before BC, respectively), while BDG testing was independent of the sampling date. No positive PCR results were obtained in sera sampled more than five days before BC. Specificities were 89% for BDG and 93% for PCR testing. In conclusion, BDG testing demonstrated several advantages over PCR testing for the diagnosis of candidemia, including higher sensitivity and earlier diagnosis. However, BC remains essential, as BDG does not allow for species differentiation.
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Affiliation(s)
- Özlem Koc
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, 80336 Munich, Germany
| | - Harald H. Kessler
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Martin Hoenigl
- Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Johannes Wagener
- Microbiology Department, St. James’s Hospital, D08 RX0X Dublin, Ireland
- Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, The University of Dublin, St. James’s Hospital Campus, D08 RX0X Dublin, Ireland
| | - Sebastian Suerbaum
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, 80336 Munich, Germany
| | - Sören Schubert
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, 80336 Munich, Germany
- Correspondence: (S.S.); (K.D.)
| | - Karl Dichtl
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, 80336 Munich, Germany
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
- Correspondence: (S.S.); (K.D.)
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The Diagnosis and Treatment of Fungal Endophthalmitis: An Update. Diagnostics (Basel) 2022; 12:diagnostics12030679. [PMID: 35328231 PMCID: PMC8947249 DOI: 10.3390/diagnostics12030679] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/26/2022] [Accepted: 03/07/2022] [Indexed: 02/04/2023] Open
Abstract
In recent, large case series of fungal endophthalmitis (FE) that were published by Asian authors, the most frequent etiologic agents for all types of FE are molds (usually Aspergillus species, while Fusarium is the prevalent etiology in keratitis-related FE). Candida was the organism found in most cases of endogenous FE. However, we must keep in mind that prevalence of fungal species varies with the geographical area. Lately, polymerase chain reaction (PCR) was increasingly used for the diagnosis of FE, allowing for very high diagnostic sensitivity, while the costs become more affordable with time. The most important shortcoming of PCR—the limited number of pathogens that can be simultaneously searched for—may be overcome by newer techniques, such as next-generation sequencing. There are even hopes of searching for genetic sequences that codify resistance to antifungals. We must not forget the potential of simpler tests (such as galactomannan and β-d-glucan) in orienting towards a diagnosis of FE. There are few reports about the use of newer antifungals in FE. Echinocandins have low penetration in the vitreous cavity, and may be of use in cases of fungal chorioretinitis (without vitritis), or injected intravitreally as an off-label, salvage therapy.
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Enz A, Mueller SC, Warnke P, Ellenrieder M, Mittelmeier W, Klinder A. Periprosthetic Fungal Infections in Severe Endoprosthetic Infections of the Hip and Knee Joint-A Retrospective Analysis of a Certified Arthroplasty Centre of Excellence. J Fungi (Basel) 2021; 7:404. [PMID: 34064002 PMCID: PMC8224054 DOI: 10.3390/jof7060404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 01/01/2023] Open
Abstract
The treatment of periprosthetic joint infections (PJI), and especially of re-infections, poses a highly complex problem in orthopaedic surgery. While fungal infections are rare, they present a special challenge. The therapy is often protracted and based on limited evidence. A total of 510 hip and knee revision surgeries were analysed for the occurrence of bacterial and fungal PJI. In patients with PJI, the duration of the hospital stay and the incidence of disarticulation of the infected joint were recorded. Out of the analysed revision arthroplasties, 43.5% were due to PJI. Monomicrobial infection occurred in 55.2%, dual microbial infection in 21.4%, and polymicrobial (≥3 different bacterial or fungal species) infection in 17.2% of the cases. Overall, Candida species were detected in 12.4% cases. Candida albicans was the main fungal pathogen. In 6.9% of cases, disarticulation of the joint was the only option to control PJI. The detection of polymicrobial infection more than doubled in follow-up revisions and there was a strong association between detection of Candida infection and disarticulation (OR 9.39). The majority of fungal infections were mixed infections of bacteria and Candida albicans. The choice of a biofilm penetrating antimycotic, e.g., caspofungin, together with a sufficient standard procedure for detection and surgical treatment can help to control the infection situation. Fungal infection often proves to be more difficult to treat than anticipated and is more frequent than expected.
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Affiliation(s)
- Andreas Enz
- Orthopaedic Clinic and Policlinic, University Medicine Rostock, 18057 Rostock, Germany; (M.E.); (W.M.); (A.K.)
| | - Silke C. Mueller
- Institute of Pharmacology and Toxicology, University Medicine Rostock, 18057 Rostock, Germany;
| | - Philipp Warnke
- Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, 18057 Rostock, Germany;
| | - Martin Ellenrieder
- Orthopaedic Clinic and Policlinic, University Medicine Rostock, 18057 Rostock, Germany; (M.E.); (W.M.); (A.K.)
| | - Wolfram Mittelmeier
- Orthopaedic Clinic and Policlinic, University Medicine Rostock, 18057 Rostock, Germany; (M.E.); (W.M.); (A.K.)
| | - Annett Klinder
- Orthopaedic Clinic and Policlinic, University Medicine Rostock, 18057 Rostock, Germany; (M.E.); (W.M.); (A.K.)
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White PL, Price JS, Cordey A, Backx M. Molecular Diagnosis of Yeast Infections. CURRENT FUNGAL INFECTION REPORTS 2021; 15:67-80. [PMID: 34178207 PMCID: PMC8212580 DOI: 10.1007/s12281-021-00421-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW The use of molecular tests to aid the diagnosis of invasive yeast infection, in particular invasive candidosis, has been described for over two decades, yet widespread application is limited, and diagnosis remains heavily dependent on classical microbiology. This article will review developments from the past decade in attempt to build on existing knowledge. It will highlight clinical performance and limitations while reviewing developments on recognized procedures; it will also provide insight into novel approaches incorporated in response to clinical demand (e.g. C. auris and antifungal resistance) or technological advances (e.g. next-generation sequencing). RECENT FINDINGS Limited methodological standardization and, until recently, unavailability of commercial options have hindered the integration of molecular diagnostics for yeasts. The development of certain, novel commercial methods has received considerable evaluation allowing a greater understanding of individual assay performance, but widespread multicentre evaluation of most commercial kits is lacking. The detection of emerging pathogens (e.g. C. auris) has been enhanced by the development of molecular tests. Molecular methods are providing a better understanding of the mycobiome, mechanisms of resistance and epidemiology/phylogeny. SUMMARY Despite over two decades of use, the incorporation of molecular methods to enhance the diagnosis of yeast infections remains limited to certain specialist centres. While the development of commercial tests will provide stimulus for broader application, further validation and reduced costs are required. Over the same period of time, Aspergillus PCR has become more widely accepted driven by international efforts to standardize methodology; it is critical that yeast PCR follows suit. Next-generation sequencing will provide significant information on the mycobiome, antifungal resistance mechanism and even broad-range detection directly from the specimen, which may be critical for the molecular detection of yeasts other than Candida species, which is currently limited.
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Affiliation(s)
- P. Lewis White
- grid.241103.50000 0001 0169 7725Mycology Reference Laboratory, Public Health Wales, Microbiology Cardiff, UHW, Heath Park, Cardiff, CF14 4XW UK
| | - Jessica S. Price
- grid.241103.50000 0001 0169 7725Mycology Reference Laboratory, Public Health Wales, Microbiology Cardiff, UHW, Heath Park, Cardiff, CF14 4XW UK
| | - Alan Cordey
- grid.241103.50000 0001 0169 7725Mycology Reference Laboratory, Public Health Wales, Microbiology Cardiff, UHW, Heath Park, Cardiff, CF14 4XW UK
| | - Matthijs Backx
- grid.241103.50000 0001 0169 7725Mycology Reference Laboratory, Public Health Wales, Microbiology Cardiff, UHW, Heath Park, Cardiff, CF14 4XW UK
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Clinical characteristics, risk factors and outcomes of mixed Candida albicans/bacterial bloodstream infections. BMC Infect Dis 2020; 20:810. [PMID: 33158426 PMCID: PMC7648279 DOI: 10.1186/s12879-020-05536-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 10/22/2020] [Indexed: 12/11/2022] Open
Abstract
Purpose The purpose of this study was to explore the clinical features, risk factors, and outcomes of mixed Candida albicans/bacterial bloodstream infections (mixed-CA/B-BSIs) compared with monomicrobial Candida albicans bloodstream infection (mono-CA-BSI) in adult patients in China. Methods All hospitalized adults with Candida albicans bloodstream infection (CA-BSI) were recruited for this retrospective observational study from January 1, 2013, to December 31, 2018. Results Of the 117 patients with CA-BSI, 24 patients (20.5%) had mixed-CA/B-BSIs. The most common copathogens were coagulase-negative Staphylococcus (CNS) (24.0%), followed by Klebsiella pneumoniae (20.0%) and Staphylococcus aureus (16.0%). In the multivariable analysis, a prior ICU stay > 2 days (adjusted odds ratio [OR], 7.445; 95% confidence interval [CI], 1.152–48.132) was an independent risk factor for mixed-CA/B-BSIs. Compared with patients with mono-CA-BSI, patients with mixed-CA/B-BSIs had a prolonged length of mechanical ventilation [17.5 (4.5, 34.8) vs. 3.0 (0.0, 24.5), p = 0.019] and prolonged length of ICU stay [22.0 (14.3, 42.2) vs. 8.0 (0.0, 31.5), p = 0.010]; however, mortality was not significantly different. Conclusions There was a high rate of mixed-CA/B-BSIs cases among CA-BSI cases, and CNS was the predominant coexisting species. A prior ICU stay > 2 days was an independent risk factor for mixed -CA/B-BSIs. Although there was no difference in mortality, the outcomes of patients with mixed -CA/B-BSIs, including prolonged length of mechanical ventilation and prolonged length of ICU stay, were worse than those with mono-CA-BSI; this deserves further attention from clinicians.
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Emerging Microbiology Diagnostics for Transplant Infections: On the Cusp of a Paradigm Shift. Transplantation 2020; 104:1358-1384. [PMID: 31972701 DOI: 10.1097/tp.0000000000003123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In light of the heightened risk for infection associated with solid organ and hematopoietic stem cell transplantation, rapid and accurate microbiology diagnostics are essential to the practice of transplant clinicians, including infectious diseases specialists. In the last decade, diagnostic microbiology has seen a shift toward culture-independent techniques including single-target and multiplexed molecular testing, mass-spectrometry, and magnetic resonance-based methods which have together greatly expanded the array of pathogens identified, increased processing speed and throughput, allowed for detection of resistance determinants, and ultimately improved the outcomes of infected transplant recipients. More recently, a newer generation of diagnostics with immense potential has emerged, including multiplexed molecular panels directly applicable to blood and blood culture specimens, next-generation metagenomics, and gas chromatography mass spectrometry. Though these methods have some recognized drawbacks, many have already demonstrated improved sensitivity and a positive impact on clinical outcomes in transplant and immunocompromised patients.
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White SK, Schmidt RL, Walker BS, Hanson KE. (1→3)-β-D-glucan testing for the detection of invasive fungal infections in immunocompromised or critically ill people. Cochrane Database Syst Rev 2020; 7:CD009833. [PMID: 32693433 PMCID: PMC7387835 DOI: 10.1002/14651858.cd009833.pub2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Invasive fungal infections (IFIs) are life-threatening opportunistic infections that occur in immunocompromised or critically ill people. Early detection and treatment of IFIs is essential to reduce morbidity and mortality in these populations. (1→3)-β-D-glucan (BDG) is a component of the fungal cell wall that can be detected in the serum of infected individuals. The serum BDG test is a way to quickly detect these infections and initiate treatment before they become life-threatening. Five different versions of the BDG test are commercially available: Fungitell, Glucatell, Wako, Fungitec-G, and Dynamiker Fungus. OBJECTIVES To compare the diagnostic accuracy of commercially available tests for serum BDG to detect selected invasive fungal infections (IFIs) among immunocompromised or critically ill people. SEARCH METHODS We searched MEDLINE (via Ovid) and Embase (via Ovid) up to 26 June 2019. We used SCOPUS to perform a forward and backward citation search of relevant articles. We placed no restriction on language or study design. SELECTION CRITERIA We included all references published on or after 1995, which is when the first commercial BDG assays became available. We considered published, peer-reviewed studies on the diagnostic test accuracy of BDG for diagnosis of fungal infections in immunocompromised people or people in intensive care that used the European Organization for Research and Treatment of Cancer (EORTC) criteria or equivalent as a reference standard. We considered all study designs (case-control, prospective consecutive cohort, and retrospective cohort studies). We excluded case studies and studies with fewer than ten participants. We also excluded animal and laboratory studies. We excluded meeting abstracts because they provided insufficient information. DATA COLLECTION AND ANALYSIS We followed the standard procedures outlined in the Cochrane Handbook for Diagnostic Test Accuracy Reviews. Two review authors independently screened studies, extracted data, and performed a quality assessment for each study. For each study, we created a 2 × 2 matrix and calculated sensitivity and specificity, as well as a 95% confidence interval (CI). We evaluated the quality of included studies using the Quality Assessment of Studies of Diagnostic Accuracy-Revised (QUADAS-2). We were unable to perform a meta-analysis due to considerable variation between studies, with the exception of Candida, so we have provided descriptive statistics such as receiver operating characteristics (ROCs) and forest plots by test brand to show variation in study results. MAIN RESULTS We included in the review 49 studies with a total of 6244 participants. About half of these studies (24/49; 49%) were conducted with people who had cancer or hematologic malignancies. Most studies (36/49; 73%) focused on the Fungitell BDG test. This was followed by Glucatell (5 studies; 10%), Wako (3 studies; 6%), Fungitec-G (3 studies; 6%), and Dynamiker (2 studies; 4%). About three-quarters of studies (79%) utilized either a prospective or a retrospective consecutive study design; the remainder used a case-control design. Based on the manufacturer's recommended cut-off levels for the Fungitell test, sensitivity ranged from 27% to 100%, and specificity from 0% to 100%. For the Glucatell assay, sensitivity ranged from 50% to 92%, and specificity ranged from 41% to 94%. Limited studies have used the Dynamiker, Wako, and Fungitec-G assays, but individual sensitivities and specificities ranged from 50% to 88%, and from 60% to 100%, respectively. Results show considerable differences between studies, even by manufacturer, which prevented a formal meta-analysis. Most studies (32/49; 65%) had no reported high risk of bias in any of the QUADAS-2 domains. The QUADAS-2 domains that had higher risk of bias included participant selection and flow and timing. AUTHORS' CONCLUSIONS We noted considerable heterogeneity between studies, and these differences precluded a formal meta-analysis. Because of wide variation in the results, it is not possible to estimate the diagnostic accuracy of the BDG test in specific settings. Future studies estimating the accuracy of BDG tests should be linked to the way the test is used in clinical practice and should clearly describe the sampling protocol and the relationship of time of testing to time of diagnosis.
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Affiliation(s)
- Sandra K White
- Department of Pathology, University of Utah, School of Medicine, Salt Lake City, Utah, USA
| | - Robert L Schmidt
- Department of Pathology, University of Utah, School of Medicine, Salt Lake City, Utah, USA
| | | | - Kimberly E Hanson
- Director, Transplant Infectious Diseases and Immunocompromised Host Service, Section Head, Clinical Microbiology, Director, Medical Microbiology Fellowship Program, University of Utah and ARUP Laboratories, Salt Lake City, Utah, USA
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Direct Blood Culturing of Candida spp. on Solid Medium by a Rapid Enrichment Method with Magnetic Beads Coated with Recombinant Human Mannan-Binding Lectin. J Clin Microbiol 2020; 58:JCM.00057-20. [PMID: 32051260 PMCID: PMC7098737 DOI: 10.1128/jcm.00057-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/02/2020] [Indexed: 12/23/2022] Open
Abstract
A rapid and accurate method to identify the species and antibiotic resistance of Candida spp. in blood is vital to increase the survival rates of patients with bloodstream infections. However, the extremely low levels of Candida spp. in blood make rapid diagnosis by standard blood culture difficult. In this study, we constructed a direct blood culturing method (i.e., the M1 method) by a rapid enrichment method with magnetic beads coated with a recombined human mannan-binding lectin (rhMBL; i. A rapid and accurate method to identify the species and antibiotic resistance of Candida spp. in blood is vital to increase the survival rates of patients with bloodstream infections. However, the extremely low levels of Candida spp. in blood make rapid diagnosis by standard blood culture difficult. In this study, we constructed a direct blood culturing method (i.e., the M1 method) by a rapid enrichment method with magnetic beads coated with a recombined human mannan-binding lectin (rhMBL; i.e., M1 protein), which demonstrated much higher Candida sp.-binding capacity than that of full-length MBL expressed in vitro (i.e., M2). With the M1 method, individual colonies were obtained before the standard blood culture method for each species of Candida spp. tested at <1 CFU/ml (an average of 29 h earlier). Additionally, the clinical sensitivity of the M1 method was 90.5% compared with that of the standard blood culture method when detecting frozen plasma from patients. More significantly, the turnaround time of the M1 method for blood culture could be reduced by approximately 37 to 43 h compared with that of the standard blood culture method in clinical sample identification.
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