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Moreno A, Mah J, Budvytiene I, Ho DY, Schwenk HT, Banaei N. Dynamics and prognostic value of plasma cell-free DNA PCR in patients with invasive aspergillosis and mucormycosis. J Clin Microbiol 2024; 62:e0039424. [PMID: 38602412 PMCID: PMC11237630 DOI: 10.1128/jcm.00394-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 03/19/2024] [Indexed: 04/12/2024] Open
Abstract
Aspergillus species and Mucorales agents are the primary etiologies of invasive fungal disease (IFD). Biomarkers that predict outcomes are needed to improve care. Patients diagnosed with invasive aspergillosis and mucormycosis using plasma cell-free DNA (cfDNA) PCR were retested weekly for 4 weeks. The primary outcome included all-cause mortality at 6 weeks and 6 months based on baseline cycle threshold (CT) values and results of follow-up cfDNA PCR testing. Forty-five patients with Aspergillus and 30 with invasive Mucorales infection were retested weekly for a total of 197 tests. Using the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSG) criteria, 30.7% (23/75), 25.3% (19/75), and 38.7% (29/75) had proven, probable, and possible IFD, respectively. In addition, 97.3% (73/75) were immunocompromised. Baseline CT increased significantly starting at week 1 for Mucorales and week 2 for Aspergillus. Aspergillosis and mucormycosis patients with higher baseline CT (CT >40 and >35, respectively) had a nonsignificantly higher survival rate at 6 weeks, compared with patients with lower baseline CT. Mucormycosis patients with higher baseline CT had a significantly higher survival rate at 6 months. Mucormycosis, but not aspergillosis patients, with repeat positive cfDNA PCR results had a nonsignificantly lower survival rate at 6 weeks and 6 months compared with patients who reverted to negative. Aspergillosis patients with baseline serum Aspergillus galactomannan index <0.5 and <1.0 had significantly higher survival rates at 6 weeks when compared with those with index ≥0.5 and ≥1.0, respectively. Baseline plasma cfDNA PCR CT can potentially be used to prognosticate survival in patients with invasive Aspergillus and Mucorales infections. IMPORTANCE We show that Aspergillus and Mucorales plasma cell-free DNA PCR can be used not only to noninvasively diagnose patients with invasive fungal disease but also to correlate the baseline cycle threshold with survival outcomes, thus potentially allowing the identification of patients at risk for poor outcomes, who may benefit from more targeted therapies.
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Affiliation(s)
- Angel Moreno
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Jordan Mah
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Indre Budvytiene
- Clinical Microbiology Laboratory, Stanford Health Care, Palo Alto, California, USA
| | - Dora Y. Ho
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Hayden T. Schwenk
- Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Niaz Banaei
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
- Clinical Microbiology Laboratory, Stanford Health Care, Palo Alto, California, USA
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
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Mah J, Nicholas V, Tayyar R, Moreno A, Murugesan K, Budvytiene I, Banaei N. Superior Accuracy of Aspergillus Plasma Cell-Free DNA Polymerase Chain Reaction Over Serum Galactomannan for the Diagnosis of Invasive Aspergillosis. Clin Infect Dis 2023; 77:1282-1290. [PMID: 37450614 DOI: 10.1093/cid/ciad420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/12/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND Invasive aspergillosis (IA) in immunocompromised hosts carries high morbidity and mortality. Diagnosis is often delayed because definitive diagnosis requires invasive specimen collection, while noninvasive testing with galactomannan is moderately accurate. Plasma cell-free DNA polymerase chain reaction (cfDNA PCR) represents a novel testing modality for the noninvasive diagnosis of invasive fungal disease (IFD). We directly compared the performance of Aspergillus plasma cfDNA PCR with serum galactomannan for the diagnosis of IA during routine clinical practice. METHODS We conducted a retrospective study of all patients with suspected IFD who had Aspergillus plasma cfDNA PCR testing at Stanford Health Care from 1 September 2020 to 30 October 2022. Patients were categorized into proven, probable, possible, and no IA based on the EORTC/MSG definitions. Primary outcomes included the clinical sensitivity and specificity for Aspergillus plasma cfDNA PCR and galactomannan. RESULTS Overall, 238 unique patients with Aspergillus plasma cfDNA PCR test results, including 63 positives and 175 nonconsecutive negatives, were included in this study. The majority were immunosuppressed (89.9%) with 22.3% 30-day all-cause mortality. The overall sensitivity and specificity of Aspergillus plasma cfDNA PCR were 86.0% (37 of 43; 95% confidence interval [CI], 72.7-95.7) and 93.1% (121 of 130; 95% CI, 87.4-96.3), respectively. The sensitivity and specificity of serum galactomannan in hematologic malignancies/stem cell transplants were 67.9% (19 of 28; 95% CI, 49.3-82.1) and 89.8% (53 of 59; 95% CI, 79.5-95.3), respectively. The sensitivity of cfDNA PCR was 93.0% (40 of 43; 95% CI, 80.9-98.5) in patients with a new diagnosis of IA. CONCLUSIONS Aspergillus plasma cfDNA PCR represents a more sensitive alternative to serum galactomannan for noninvasive diagnosis of IA.
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Affiliation(s)
- Jordan Mah
- Division of Pathology, Stanford University School of Medicine, Stanford, California, USA
- Clinical Microbiology Laboratory, Stanford Health Care, Stanford, California, USA
| | - Veronica Nicholas
- Division of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Ralph Tayyar
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Angel Moreno
- Division of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Kanagavel Murugesan
- Division of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Indre Budvytiene
- Clinical Microbiology Laboratory, Stanford Health Care, Stanford, California, USA
| | - Niaz Banaei
- Division of Pathology, Stanford University School of Medicine, Stanford, California, USA
- Clinical Microbiology Laboratory, Stanford Health Care, Stanford, California, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
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Cruciani M, White PL, Barnes RA, Loeffler J, Donnelly JP, Rogers TR, Heinz WJ, Warris A, Morton CO, Lengerova M, Klingspor L, Sendid B, Lockhart DEA. An Overview of Systematic Reviews of Polymerase Chain Reaction (PCR) for the Diagnosis of Invasive Aspergillosis in Immunocompromised People: A Report of the Fungal PCR Initiative (FPCRI)-An ISHAM Working Group. J Fungi (Basel) 2023; 9:967. [PMID: 37888223 PMCID: PMC10607919 DOI: 10.3390/jof9100967] [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: 07/03/2023] [Revised: 09/11/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023] Open
Abstract
This overview of reviews (i.e., an umbrella review) is designed to reappraise the validity of systematic reviews (SRs) and meta-analyses related to the performance of Aspergillus PCR tests for the diagnosis of invasive aspergillosis in immunocompromised patients. The methodological quality of the SRs was assessed using the AMSTAR-2 checklist; the quality of the evidence (QOE) within each SR was appraised following the GRADE approach. Eight out of 12 SRs were evaluated for qualitative and quantitative assessment. Five SRs evaluated Aspergillus PCR on bronchoalveolar lavage fluid (BAL) and three on blood specimens. The eight SRs included 167 overlapping reports (59 evaluating PCR in blood specimens, and 108 in BAL), based on 107 individual primary studies (98 trials with a cohort design, and 19 with a case-control design). In BAL specimens, the mean sensitivity and specificity ranged from 0.57 to 0.91, and from 0.92 to 0.97, respectively (QOE: very low to low). In blood specimens (whole blood or serum), the mean sensitivity ranged from 0.57 to 0.84, and the mean specificity from 0.58 to 0.95 (QOE: low to moderate). Across studies, only a low proportion of AMSTAR-2 critical domains were unmet (1.8%), demonstrating a high quality of methodological assessment. Conclusions. Based on the overall methodological assessment of the reviews included, on average we can have high confidence in the quality of results generated by the SRs.
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Affiliation(s)
| | - P. Lewis White
- Public Health Wales, Microbiology Cardiff, UK and Centre for Trials Research, Division of Infection and Immunity, Cardiff University, Cardiff CF14 4XW, UK;
| | | | - Juergen Loeffler
- Department of Internal Medicine II, University Hospital of Würzburg, 97070 Würzburg, Germany
| | | | - Thomas R. Rogers
- Discipline of Clinical Microbiology, Trinity College Dublin, St. James’s Hospital Campus, LS9 7TF Dublin, Ireland;
| | - Werner J. Heinz
- Medicine Clinic II, Caritas Hospital Bad Mergentheim, 97980 Bad Mergentheim, Germany
| | - Adilia Warris
- MRC Centre for Medical Mycology, University of Exeter, Exeter EX4 4QJ, UK;
| | - Charles Oliver Morton
- School of Science, Western Sydney University, Campbelltown Campus, Campbelltown, NSW 2751, Australia;
| | - Martina Lengerova
- Central European Institute of Technology, Masaryk University, 60177 Brno, Czech Republic
| | - Lena Klingspor
- Department of Laboratory Medicine, Karolinska Institutet, 17177 Stockholm, Sweden;
| | - Boualem Sendid
- Inserm U1285, CNRS UMR 8576, UGSF, CHU Lille, Laboratoire de Parasitologie-Mycologie, University of Lille, 59000 Lille, France;
| | - Deborah E. A. Lockhart
- Institute of Medical Sciences, School of Medicine Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB24 3FX, UK
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Keri VC, Chandrasekar PH. Polymerase chain reaction in the diagnosis of invasive aspergillosis: approaches for appropriate use. Leuk Lymphoma 2023; 64:1330-1334. [PMID: 37211858 DOI: 10.1080/10428194.2023.2209683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/09/2023] [Accepted: 04/19/2023] [Indexed: 05/23/2023]
Abstract
Detection of aspergillus by PCR is a helpful tool for early diagnosis. The test has excellent sensitivity and specificity with a high negative predictive value. Well-accepted, standardized method for DNA extraction for PCR testing is to be adopted for all commercial assays and conclusive validation data are awaited in varied clinical settings. This perspective offers guidance for utilizing PCR testing while awaiting such data. Quantification by PCR, species-specific identification assays and detection of resistance genetic markers are of future promise. Herein, we summarize the available data on aspergillus PCR and describe its potential utility through a clinical case scenario-based approach.
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Affiliation(s)
- Vishakh C Keri
- Division of Infectious diseases, Wayne State University, Detroit, MI, USA
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Jenks JD, White PL, Kidd SE, Goshia T, Fraley SI, Hoenigl M, Thompson GR. An update on current and novel molecular diagnostics for the diagnosis of invasive fungal infections. Expert Rev Mol Diagn 2023; 23:1135-1152. [PMID: 37801397 PMCID: PMC10842420 DOI: 10.1080/14737159.2023.2267977] [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: 07/07/2023] [Accepted: 10/04/2023] [Indexed: 10/08/2023]
Abstract
BACKGROUND Invasive fungal infections cause millions of infections annually, but diagnosis remains challenging. There is an increased need for low-cost, easy to use, highly sensitive and specific molecular assays that can differentiate between colonized and pathogenic organisms from different clinical specimens. AREAS COVERED We reviewed the literature evaluating the current state of molecular diagnostics for invasive fungal infections, focusing on current and novel molecular tests such as polymerase chain reaction (PCR), digital PCR, high-resolution melt (HRM), and metagenomics/next generation sequencing (mNGS). EXPERT OPINION PCR is highly sensitive and specific, although performance can be impacted by prior/concurrent antifungal use. PCR assays can identify mutations associated with antifungal resistance, non-Aspergillus mold infections, and infections from endemic fungi. HRM is a rapid and highly sensitive diagnostic modality that can identify a wide range of fungal pathogens, including down to the species level, but multiplex assays are limited and HRM is currently unavailable in most healthcare settings, although universal HRM is working to overcome this limitation. mNGS offers a promising approach for rapid and hypothesis-free diagnosis of a wide range of fungal pathogens, although some drawbacks include limited access, variable performance across platforms, the expertise and costs associated with this method, and long turnaround times in real-world settings.
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Affiliation(s)
- Jeffrey D Jenks
- Durham County Department of Public Health, Durham, North Carolina, USA
- Division of Infectious Diseases, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - P Lewis White
- Public Health Wales Microbiology Cardiff, UHW, United Kingdom and Centre for trials research/Division of Infection/Immunity, Cardiff University, Cardiff, UK
| | - Sarah E Kidd
- National Mycology Reference Centre, SA Pathology, Adelaide, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, Australia
| | - Tyler Goshia
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Stephanie I Fraley
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Martin Hoenigl
- Division of Infectious Diseases, Medical University of Graz, Graz, Austria
- BioTechMed, Graz, Austria
| | - George R Thompson
- University of California Davis Center for Valley Fever, Sacramento, CA, USA
- Department of Internal Medicine, Division of Infectious Diseases, University of California Davis Medical Center, Sacramento, CA, USA
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, CA, USA
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White PL, Alanio A, Brown L, Cruciani M, Hagen F, Gorton R, Lackner M, Millon L, Morton CO, Rautemaa-Richardson R, Barnes RA, Donnelly JP, Loffler J. An overview of using fungal DNA for the diagnosis of invasive mycoses. Expert Rev Mol Diagn 2022; 22:169-184. [PMID: 35130460 DOI: 10.1080/14737159.2022.2037423] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Fungal PCR has undergone considerable standardization and together with the availability of commercial assays, external quality assessment schemes and extensive performance validation data, is ready for widespread use for the screening and diagnosis of invasive fungal disease (IFD). AREAS COVERED Drawing on the experience and knowledge of the leads of the various working parties of the Fungal PCR initiative, this review will address general considerations concerning the use of molecular tests for the diagnosis of IFD, before focussing specifically on the technical and clinical aspects of molecular testing for the main causes of IFD and recent technological developments. EXPERT OPINION For infections caused by Aspergillus, Candida and Pneumocystis jirovecii, PCR testing is recommended, combination with serological testing will likely enhance the diagnosis of these diseases. For other IFD (e.g. Mucormycosis) molecular diagnostics, represent the only non-classical mycological approach towards diagnoses and continued performance validation and standardization has improved confidence in such testing. The emergence of antifungal resistance can be diagnosed, in part, through molecular testing. Next-generation sequencing has the potential to significantly improve our understanding of fungal phylogeny, epidemiology, pathogenesis, mycobiome/microbiome and interactions with the host, while identifying novel and existing mechanisms of antifungal resistance and novel diagnostic/therapeutic targets.
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Affiliation(s)
- P Lewis White
- Public Health Wales Microbiology Cardiff, UHW, Cardiff, UK CF14 4XW
| | - Alexandre Alanio
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.,Université de Paris, Paris, France.,Institut Pasteur, CNRS UMR2000, Unité de Mycologie Moléculaire, Centre National de Reference Mycoses invasives et Antifongiques, Paris, France
| | - Lottie Brown
- NHS Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Wythenshawe Hospital; and Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | | | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands & Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rebecca Gorton
- Dept. of Infection Sciences, Health Services Laboratories (HSL) LLP, London, UK
| | - Michaela Lackner
- Institute of Hygiene and Medical Microbiology, Department of Hygiene, Medical Microbiology and Publics Health, Medical University Innsbruck, Innsbruck, Austria
| | - Laurence Millon
- Parasitology-Mycology Department, University Hospital of Besançon, 25000 Besançon, France.,UMR 6249 CNRS Chrono-Environnement, University of Bourgogne Franche-Comté, 25000 Besançon, France
| | - C Oliver Morton
- Western Sydney University, School of Science, Campbelltown, NSW 2560, Australia
| | - Riina Rautemaa-Richardson
- NHS Mycology Reference Centre Manchester, ECMM Centre of Excellence, Manchester University NHS Foundation Trust, Wythenshawe Hospital; and Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | | | | | - Juergen Loffler
- Department of Internal Medicine II, WÜ4i, University Hospital Wuerzburg, Wuerzburg, Germany
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Recognition of Diagnostic Gaps for Laboratory Diagnosis of Fungal Diseases: Expert Opinion from the Fungal Diagnostics Laboratories Consortium (FDLC). J Clin Microbiol 2021; 59:e0178420. [PMID: 33504591 DOI: 10.1128/jcm.01784-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fungal infections are a rising threat to our immunocompromised patient population, as well as other nonimmunocompromised patients with various medical conditions. However, little progress has been made in the past decade to improve fungal diagnostics. To jointly address this diagnostic challenge, the Fungal Diagnostics Laboratory Consortium (FDLC) was recently created. The FDLC consists of 26 laboratories from the United States and Canada that routinely provide fungal diagnostic services for patient care. A survey of fungal diagnostic capacity among the 26 members of the FDLC was recently completed, identifying the following diagnostic gaps: lack of molecular detection of mucormycosis; lack of an optimal diagnostic algorithm incorporating fungal biomarkers and molecular tools for early and accurate diagnosis of Pneumocystis pneumonia, aspergillosis, candidemia, and endemic mycoses; lack of a standardized molecular approach to identify fungal pathogens directly in formalin-fixed paraffin-embedded tissues; lack of robust databases to enhance mold identification with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; suboptimal diagnostic approaches for mold blood cultures, tissue culture processing for Mucorales, and fungal respiratory cultures for cystic fibrosis patients; inadequate capacity for fungal point-of-care testing to detect and identify new, emerging or underrecognized, rare, or uncommon fungal pathogens; and performance of antifungal susceptibility testing. In this commentary, the FDLC delineates the most pressing unmet diagnostic needs and provides expert opinion on how to fulfill them. Most importantly, the FDLC provides a robust laboratory network to tackle these diagnostic gaps and ultimately to improve and enhance the clinical laboratory's capability to rapidly and accurately diagnose fungal infections.
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White PL, Bretagne S, Caliendo AM, Loeffler J, Patterson TF, Slavin M, Wingard JR. Aspergillus Polymerase Chain Reaction-An Update on Technical Recommendations, Clinical Applications, and Justification for Inclusion in the Second Revision of the EORTC/MSGERC Definitions of Invasive Fungal Disease. Clin Infect Dis 2021; 72:S95-S101. [PMID: 33709129 DOI: 10.1093/cid/ciaa1865] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Aspergillus polymerase chain reaction testing of blood and respiratory samples has recently been included in the second revision of the EORTC/MSGERC definitions for classifying invasive fungal disease. This is a result of considerable efforts to standardize methodology, the availability of commercial assays and external quality control programs, and additional clinical validation. This supporting article provides both clinical and technical justifications for its inclusion while also summarizing recent advances and likely future developments in the molecular diagnosis of invasive aspergillosis.
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Affiliation(s)
- P Lewis White
- Public Health Wales Mycology Reference Laboratory, Cardiff, United Kingdom
| | - Stephane Bretagne
- Mycology Laboratory, Saint Louis Hospital, Paris and Université de Paris, France
| | - Angela M Caliendo
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Juergen Loeffler
- Department of Molecular Biology and Infection, University Hospital Wuerzburg, Medical Hospital II, Wuerzburg, Germany
| | - Thomas F Patterson
- Department of Medicine, University of Texas Health San Antonio and the South Texas Veterans Health Care System, San Antonio, Texas, USA
| | - Monica Slavin
- National Centre for Infections in Cancer, Sir Peter MacCallum Department of Medical Oncology, University of Melbourne, Melbourne, Australia
| | - John R Wingard
- Department of Medicine, University of Florida College of Medicine, Gainesville, Florida, USA
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Recent Advances and Novel Approaches in Laboratory-Based Diagnostic Mycology. J Fungi (Basel) 2021; 7:jof7010041. [PMID: 33440757 PMCID: PMC7827937 DOI: 10.3390/jof7010041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/31/2020] [Accepted: 01/01/2021] [Indexed: 12/16/2022] Open
Abstract
What was once just culture and microscopy the field of diagnostic mycology has significantly advanced in recent years and continues to incorporate novel assays and strategies to meet the changes in clinical demand. The emergence of widespread resistance to antifungal therapy has led to the development of a range of molecular tests that target mutations associated with phenotypic resistance, to complement classical susceptibility testing and initial applications of next-generation sequencing are being described. Lateral flow assays provide rapid results, with simplicity allowing the test to be performed outside specialist centres, potentially as point-of-care tests. Mycology has responded positively to an ever-diversifying patient population by rapidly identifying risk and developing diagnostic strategies to improve patient management. Nowadays, the diagnostic repertoire of the mycology laboratory employs classical, molecular and serological tests and should be keen to embrace diagnostic advancements that can improve diagnosis in this notoriously difficult field.
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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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Carvalho-Pereira J, Fernandes F, Araújo R, Springer J, Loeffler J, Buitrago MJ, Pais C, Sampaio P. Multiplex PCR Based Strategy for Detection of Fungal Pathogen DNA in Patients with Suspected Invasive Fungal Infections. J Fungi (Basel) 2020; 6:E308. [PMID: 33238439 PMCID: PMC7712097 DOI: 10.3390/jof6040308] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/15/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022] Open
Abstract
A new and easy polymerase chain reaction (PCR) multiplex strategy, for the identification of the most common fungal species involved in invasive fungal infections (IFI) was developed in this work. Two panels with species-specific markers were designed, the Candida Panel for the identification of Candida species, and the Filamentous Fungi Panel for the identification of Aspergillus species and Rhizopusarrhizus. The method allowed the correct identification of all targeted pathogens using extracted DNA or by colony PCR, showed no cross-reactivity with nontargeted species and allowed identification of different species in mixed infections. Sensitivity reached 10 to 1 pg of DNA and was suitable for clinical samples from sterile sites, with a sensitivity of 89% and specificity of 100%. Overall, the study showed that the new method is suitable for the identification of the ten most important fungal species involved in IFI, not only from positive blood cultures but also from clinical samples from sterile sites. The method provides a unique characteristic, of seeing the peak in the specific region of the panel with the correct fluorescence dye, that aids the ruling out of unspecific amplifications. Furthermore, the panels can be further customized, selecting markers for different species and/or resistance genes.
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Affiliation(s)
- Joana Carvalho-Pereira
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710 Braga, Portugal; (J.C.-P.); (F.F.); (C.P.)
| | - Filipa Fernandes
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710 Braga, Portugal; (J.C.-P.); (F.F.); (C.P.)
| | - Ricardo Araújo
- Department Medical Biotechnology, Health Sciences, Flinders University, Adelaide 5042, Australia;
| | - Jan Springer
- Department of Internal Medicine II, University Hospital of Würzburg, 97080 Würzburg, Germany; (J.S.); (J.L.)
| | - Juergen Loeffler
- Department of Internal Medicine II, University Hospital of Würzburg, 97080 Würzburg, Germany; (J.S.); (J.L.)
| | - María José Buitrago
- Mycology Reference Laboratory, National Centre of Microbiology, Instituto de Salud Carlos III, 28220 Madrid, Spain;
| | - Célia Pais
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710 Braga, Portugal; (J.C.-P.); (F.F.); (C.P.)
| | - Paula Sampaio
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710 Braga, Portugal; (J.C.-P.); (F.F.); (C.P.)
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12
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Scharf S, Bartels A, Kondakci M, Pfeffer K, Henrich B, Haas R. Introduction of a bead beating step improves fungal DNA extraction from selected patient specimens. Int J Med Microbiol 2020; 310:151443. [PMID: 32862838 DOI: 10.1016/j.ijmm.2020.151443] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/25/2020] [Accepted: 07/20/2020] [Indexed: 12/11/2022] Open
Abstract
In immunocompromised patients a colonisation with fungi carries the risk to develop serious invasive fungal infection. An early detection is therefore important, but not optimal hitherto. Fortunately, molecular genetic methods have increased the sensitivity of fungal detection and limited the time, until results are available. However, their success depends on an efficient extraction of genomic DNA from the fungal cell in the given diagnostic specimen. To improve the routine DNA preparation method for yeasts and moulds, the impact of bead beating on fungal DNA release was evaluated. PBS, blood and respiratory rinse were spiked with Candida glabrata or Aspergillus fumigatus. DNA was extracted by mechanical bead beating in addition to the different steps of the DNA preparation protocol, which comprised liquid nitrogen treatment, proteinase K digestion and DNA isolation using the EZ1 DNA Tissue Kit and Workstation. In every method variant tested, treatment with liquid nitrogen did not improve the DNA release. Bead beating once followed by proteinase K digestion and EZ1-work-up led to the highest DNA release from fungus, spiked in PBS, and increased the extracted DNA amount of C. glabrata about 100-fold and of A. fumigatus about 10-fold in relation to sole EZ1-work-up. In fungus-spiked respiratory rinse and blood, highest increase in DNA release was measured after triple bead beating with simultaneous proteinase K digestion. Fungal DNA release of C. glabrata increased for >100-fold in respiratory rinse and for >1000-fold in blood and of A. fumigatus for >10-fold in respiratory rinse and about 5- to 10-fold in blood. The data of this study clearly demonstrate that preparation of fungal DNA from human specimens is optimized by introduction of a bead beating step to the conventional DNA-preparation method without the necessity of a liquid nitrogen step.
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Affiliation(s)
- Sebastian Scharf
- Institute of Medical Microbiology and Hospital Hygiene, University of Duesseldorf, Germany; Department of Haematology, Oncology and Clinical Immunology, University of Duesseldorf, Medical Faculty, Duesseldorf, Germany
| | - Anna Bartels
- Department of Haematology, Oncology and Clinical Immunology, University of Duesseldorf, Medical Faculty, Duesseldorf, Germany
| | - Mustafa Kondakci
- Department of Haematology, Oncology and Clinical Immunology, University of Duesseldorf, Medical Faculty, Duesseldorf, Germany
| | - Klaus Pfeffer
- Institute of Medical Microbiology and Hospital Hygiene, University of Duesseldorf, Germany
| | - Birgit Henrich
- Institute of Medical Microbiology and Hospital Hygiene, University of Duesseldorf, Germany.
| | - Rainer Haas
- Department of Haematology, Oncology and Clinical Immunology, University of Duesseldorf, Medical Faculty, Duesseldorf, Germany
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13
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Barnes R, Rogers T, Maertens J. Defining standards of CARE for invasive fungal diseases in adult haematology patients: antifungal prophylaxis versus treatment. J Antimicrob Chemother 2020; 74:ii21-ii26. [PMID: 31222310 DOI: 10.1093/jac/dkz040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Despite the availability of four different classes of antifungal agents, invasive fungal infections, in particular mould diseases, continue to have a high crude mortality rate in adult haematology patients, especially when diagnosed late. Early diagnosis, resulting in prompt and adequate antifungal intervention, is of great importance when trying to improve the overall outcome of these infections, but depends on the availability of rapid and sensitive diagnostic tools. The medical community has developed and continues to evaluate a continuum of antifungal strategies (starting with prophylaxis followed by empirical therapy and more recently a diagnostic-driven or pre-emptive approach) to better tackle these life-threatening diseases. While the empirical approach seems to have lost some of its popularity, the jury is still out about the pros and cons of universal antifungal prophylaxis in at-risk adult haematology patients compared with an approach that uses radiological and mycological diagnostic methods with good to excellent negative predictive values (also erroneously called pre-emptive), trying to exclude the presence of an invasive fungal disease. Whilst awaiting the results of comparative clinical studies, believers and non-believers around the globe continue to argue about the advantages and shortcomings of both strategies. The debate presented here provides a rationale for both prophylaxis for 'high-risk' haematology patients as well as for a more targeted approach based on the appropriate use of mycological, radiological, immunological (and genetic) methods for the diagnosis of invasive fungal diseases.
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Affiliation(s)
- Rosemary Barnes
- Department of Medical Microbiology and Infectious Diseases, Cardiff University, Cardiff, UK
| | - Thomas Rogers
- Department of Clinical Microbiology, Trinity College Dublin & St. James's Hospital, Dublin, Ireland
| | - Johan Maertens
- Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium.,Clinical Department of Haematology, UZ Leuven, Leuven, Belgium
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14
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Egger M, Jenks JD, Hoenigl M, Prattes J. Blood Aspergillus PCR: The Good, the Bad, and the Ugly. J Fungi (Basel) 2020; 6:jof6010018. [PMID: 32012787 PMCID: PMC7151127 DOI: 10.3390/jof6010018] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/11/2022] Open
Abstract
Invasive Aspergillosis (IA) is one of the most common invasive fungal diseases and is accompanied by high morbidity and mortality. In order to maximize patient outcomes and survival, early and rapid diagnosis has been shown to be pivotal. Hence, diagnostic tools aiding and improving the diagnostic process are ambitiously searched for. In this context, polymerase chain reaction (PCR) may represent a potential candidate. Its additional value and benefits in diagnosis have been demonstrated and are scientifically established. Nevertheless, standardized and widespread usage is sparse because several factors influence diagnostic quality and need to be considered in order to optimize diagnostic performance and outcome. In the following review, the current role of PCR in the diagnosis of IA is explored, with special focus on the strengths and limitations of PCR in different settings.
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Affiliation(s)
- Matthias Egger
- Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, 8036 Graz, Austria; (M.E.); (M.H.)
| | - Jeffrey D. Jenks
- Department of Medicine, University of California San Diego, San Diego, CA 92093, USA;
- Clinical and Translational Fungal Research Group, University of California San Diego, San Diego, CA 92093, USA
| | - Martin Hoenigl
- Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, 8036 Graz, Austria; (M.E.); (M.H.)
- Department of Medicine, University of California San Diego, San Diego, CA 92093, USA;
- Clinical and Translational Fungal Research Group, University of California San Diego, San Diego, CA 92093, USA
| | - Juergen Prattes
- Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, 8036 Graz, Austria; (M.E.); (M.H.)
- Correspondence: ; Tel.: +43-316-385-30046
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15
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16
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Kidd SE, Chen SCA, Meyer W, Halliday CL. A New Age in Molecular Diagnostics for Invasive Fungal Disease: Are We Ready? Front Microbiol 2020; 10:2903. [PMID: 31993022 PMCID: PMC6971168 DOI: 10.3389/fmicb.2019.02903] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 12/02/2019] [Indexed: 12/18/2022] Open
Abstract
Invasive fungal diseases (IFDs) present an increasing global burden in immunocompromised and other seriously ill populations, including those caused by pathogens which are inherently resistant or less susceptible to antifungal drugs. Early diagnosis encompassing accurate detection and identification of the causative agent and of antifungal resistance is critical for optimum patient outcomes. Many molecular-based diagnostic approaches have good clinical utility although interpretation of results should be according to clinical context. Where an IFD is in the differential diagnosis, panfungal PCR assays allow the rapid detection/identification of fungal species directly from clinical specimens with good specificity; sensitivity is also high when hyphae are seen in the specimen including in paraffin-embedded tissue. Aspergillus PCR assays on blood fractions have good utility in the screening of high risk hematology patients with high negative predictive value (NPV) and positive predictive value (PPV) of 94 and 70%, respectively, when two positive PCR results are obtained. The standardization, and commercialization of Aspergillus PCR assays has now enabled direct comparison of results between laboratories with commercial assays also offering the simultaneous detection of common azole resistance mutations. Candida PCR assays are not as well standardized with the only FDA-approved commercial system (T2Candida) detecting only the five most common species; while the T2Candida outperforms blood culture in patients with candidemia, its role in routine Candida diagnostics is not well defined. There is growing use of Mucorales-specific PCR assays to detect selected genera in blood fractions. Quantitative real-time Pneumocystis jirovecii PCRs have replaced microscopy and immunofluorescent stains in many diagnostic laboratories although distinguishing infection may be problematic in non-HIV-infected patients. For species identification of isolates, DNA barcoding with dual loci (ITS and TEF1α) offer optimal accuracy while next generation sequencing (NGS) technologies offer highly discriminatory analysis of genetic diversity including for outbreak investigation and for drug resistance characterization. Advances in molecular technologies will further enhance routine fungal diagnostics.
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Affiliation(s)
- Sarah E. Kidd
- National Mycology Reference Centre, Microbiology and Infectious Diseases, South Australia Pathology, Adelaide, SA, Australia
| | - Sharon C.-A. Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, New South Wales Health Pathology, Westmead Hospital, Westmead, NSW, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
| | - Wieland Meyer
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Faculty of Medicine and Health, Westmead Clinical School, The University of Sydney, Sydney, NSW, Australia
- The Westmead Institute for Medical Research, Westmead, NSW, Australia
- Research and Education Network, Westmead Hospital, Westmead, NSW, Australia
| | - Catriona L. Halliday
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, New South Wales Health Pathology, Westmead Hospital, Westmead, NSW, Australia
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17
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El-Kamand S, Papanicolaou A, Morton CO. The Use of Whole Genome and Next-Generation Sequencing in the Diagnosis of Invasive Fungal Disease. CURRENT FUNGAL INFECTION REPORTS 2019. [DOI: 10.1007/s12281-019-00363-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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18
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Young BA, Hanson KE, Gomez CA. Molecular Diagnostic Advances in Transplant Infectious Diseases. Curr Infect Dis Rep 2019; 21:52. [PMID: 31773290 DOI: 10.1007/s11908-019-0704-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW The infectious complications of transplantation can have devastating consequences for patients. Early and accurate diagnosis is essential to good outcomes. This review describes recent advances in pathogen-directed diagnostic testing and discusses the role of new methods for transplant infectious diseases. RECENT FINDINGS Several molecular assays have been introduced into clinical practice in recent years. When the results of rapid testing are linked to patient-specific interventions, improved outcomes can be realized. Syndromic testing along with metagenomic next-generation sequencing (mNGS) represents novel approaches to infection diagnosis. However, the optimal use of these tests for transplant patients along with an overall assessment of cost-effectiveness demands further study. Molecular diagnostics are revolutionizing transplant care. Clinicians need to be aware of the current diagnostic landscape and have a working knowledge of the nuances related to test performance, result interpretation, and cost.
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Affiliation(s)
- Brittany A Young
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,Associated Regional and University Pathologists Laboratories (ARUP), Salt Lake City, UT, USA
| | - Kimberly E Hanson
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,Associated Regional and University Pathologists Laboratories (ARUP), Salt Lake City, UT, USA.,Department of Medicine, Division of Infectious Diseases, University of Utah, Salt Lake City, UT, USA
| | - Carlos A Gomez
- Department of Medicine, Division of Infectious Diseases, University of Utah, Salt Lake City, UT, USA. .,University of Utah School of Medicine, 30 North 1900 East, Room 4B319, Salt Lake City, UT, 84132, USA.
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19
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Krifors A, Özenci V, Ullberg M, Ackefors M, Jädersten M, Strålin K, Blennow O. PCR with electrospray ionization-mass spectrometry on bronchoalveolar lavage for detection of invasive mold infections in hematological patients. PLoS One 2019; 14:e0212812. [PMID: 30794675 PMCID: PMC6386253 DOI: 10.1371/journal.pone.0212812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/08/2019] [Indexed: 02/04/2023] Open
Abstract
Invasive mold infections are life-threatening complications in patients with hematological malignancies. Conventional microbiological methods for diagnosing invasive pulmonary mold infections have low sensitivity, and molecular methods are being developed. Detection of molds using PCR with a narrow spectrum has been reported, but data with broad-spectrum PCR are lacking. In this study, the diagnostic performance and utility of a broad-spectrum PCR (broad-spectrum PCR with subsequent electrospray ionization-mass spectrometry, PCR/ESI-MS) for detection of molds in bronchoalveolar lavage (BAL) in 27 hematological patients with a new pulmonary infiltrate was analyzed. Using the revised EORTC/MSG criteria, PCR/ESI-MS was the only positive microbiological test in patients with proven invasive mold infection (n = 2) and correctly identified all cases of probable invasive pulmonary aspergillosis (n = 5). In patients with a possible invasive mold infection (n = 5), PCR/ESI-MS was positive in three patients. Mucorales was identified with PCR/ESI-MS in four patients that were all culture negative. The PCR/ESI-MS results had a clinical impact on antifungal therapy in 12 (44%) of the patients: modification of treatment in 6 (22%) patients and discontinuation in 6 (22%) patients. This study provides proof of concept that routine use of a broad-spectrum PCR for molds in bronchoalveolar lavage in immunocompromised patients is sensitive, fast, and has an impact on clinical decision-making.
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Affiliation(s)
- Anders Krifors
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
| | - Volkan Özenci
- Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Måns Ullberg
- Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Malin Ackefors
- Department of Infectious Diseases, Karolinska University Hospital, Huddinge, Sweden
| | - Martin Jädersten
- Centre for Haematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Kristoffer Strålin
- Department of Infectious Diseases, Karolinska University Hospital, Huddinge, Sweden
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Ola Blennow
- Department of Infectious Diseases, Karolinska University Hospital, Huddinge, Sweden
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
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20
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Barnes RA, White PL, Morton CO, Rogers TR, Cruciani M, Loeffler J, Donnelly JP. Diagnosis of aspergillosis by PCR: Clinical considerations and technical tips. Med Mycol 2018; 56:60-72. [PMID: 29087518 DOI: 10.1093/mmy/myx091] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/29/2017] [Indexed: 12/25/2022] Open
Abstract
Standardization of Aspergillus polymerase chain reaction (PCR) protocols has progressed, and analytical validity of blood-based assays has been formally established. It remains necessary to consider how the tests can be used in practice to maximize clinical utility. To determine the optimal diagnostic strategies and influence on patient management, several factors require consideration, including the patient population, incidence of invasive aspergillosis (and other fungal disease), and the local antifungal prescribing policy. Technical issues such as specimen type, ease of sampling, frequency of testing, access to testing centers, and time to reporting will also influence the use of PCR in clinical practice. Interpretation of all diagnostic tests is dependent on the clinical context and molecular assays are no exception, but with the proposal to incorporate Aspergillus PCR into the second revision of the consensus guidelines for defining invasive fungal disease the acceptance and understanding of molecular tests should improve.
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Affiliation(s)
| | - P Lewis White
- Public Health Wales Microbiology Cardiff, Cardiff, UK
| | | | | | - Mario Cruciani
- Center of Community Medicine and Infectious Diseases Service, ULSS 20 Verona
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21
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Fréalle E, Gosset P, Leroy S, Delattre C, Wacrenier A, Zenzmaier C, Zawadzki C, Aliouat EM, Perkhofer S. In vitro coagulation triggers anti-Aspergillus fumigatus neutrophil response. Future Microbiol 2018; 13:659-669. [PMID: 29790796 DOI: 10.2217/fmb-2017-0190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
AIM To explore Aspergillus interactions with platelets in the blood, especially during clot formation. MATERIALS & METHODS Aspergillus fumigatus resting or swollen conidia, germlings or hyphae were inoculated into blood sampled into tubes with or without anticoagulant. Interactions were explored using microscopy, and chemokine levels were determined. RESULTS Anatomopathological examination of the clot revealed conidia and germlings colocalization with platelet aggregates, and neutrophil recruitment around aggregates. Transmission electron microscopy showed conidia and hyphae surrounded by neutrophils. Increased CCL5 and CXCL4 when conidia or germlings but not hyphae were added suggested they could be involved in neutrophil recruitment around aggregates. CONCLUSION These data suggest platelets could trigger coagulopathy and activate neutrophils during aspergillosis. They open up new perspectives for aspergillosis management.
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Affiliation(s)
- Emilie Fréalle
- Univ Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, F-59000 Lille, France.,CHU Lille, Laboratoire de Parasitologie-Mycologie, F-59000 Lille, France
| | - Philippe Gosset
- Univ Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, F-59000 Lille, France
| | - Sophie Leroy
- CHU Lille, Laboratoire de Parasitologie-Mycologie, F-59000 Lille, France
| | - Claire Delattre
- CHU Lille, Laboratoire d'Anatomopathologie, F-59000 Lille, France
| | - Agnès Wacrenier
- CHU Lille, Laboratoire d'Anatomopathologie, F-59000 Lille, France
| | | | - Christophe Zawadzki
- CHU Lille, Laboratoire d'Hématologie & Univ. Lille, Inserm, Institut Pasteur, U1011, F-59000 Lille, France
| | - El Moukhtar Aliouat
- Univ Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, F-59000 Lille, France.,Laboratoire de Parasitologie, Faculté de Pharmacie de Lille - Univ Lille, France
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22
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Fidler G, Kocsube S, Leiter E, Biro S, Paholcsek M. DNA Barcoding Coupled with High Resolution Melting Analysis Enables Rapid and Accurate Distinction of Aspergillus species. Med Mycol 2018; 55:642-659. [PMID: 27915305 DOI: 10.1093/mmy/myw127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 10/17/2016] [Indexed: 01/24/2023] Open
Abstract
We describe a high-resolution melting (HRM) analysis method that is rapid, reproducible, and able to identify reference strains and further 40 clinical isolates of Aspergillus fumigatus (14), A. lentulus (3), A. terreus (7), A. flavus (8), A. niger (2), A. welwitschiae (4), and A. tubingensis (2). Asp1 and Asp2 primer sets were designed to amplify partial sequences of the Aspergillus benA (beta-tubulin) genes in a closed-, single-tube system. Human placenta DNA, further Aspergillus (3), Candida (9), Fusarium (6), and Scedosporium (2) nucleic acids from type strains and clinical isolates were also included in this study to evaluate cross reactivity with other relevant pathogens causing invasive fungal infections. The barcoding capacity of this method proved to be 100% providing distinctive binomial scores; 14, 34, 36, 35, 25, 15, 26 when tested among species, while the within-species distinction capacity of the assay proved to be 0% based on the aligned thermodynamic profiles of the Asp1, Asp2 melting clusters allowing accurate species delimitation of all tested clinical isolates. The identification limit of this HRM assay was also estimated on Aspergillus reference gDNA panels where it proved to be 10-102 genomic equivalents (GE) except the A. fumigatus panel where it was 103 only. Furthermore, misidentification was not detected with human genomic DNA or with Candida, Fusarium, and Scedosporium strains. Our DNA barcoding assay introduced here provides results within a few hours, and it may possess further diagnostic utility when analyzing standard cultures supporting adequate therapeutic decisions.
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Affiliation(s)
- Gabor Fidler
- University of Debrecen, Faculty of Medicine, Department of Human Genetics, Debrecen, Hungary
| | - Sandor Kocsube
- University of Szeged, Faculty of Science & Informatics, Department of Microbiology, Szeged, Hungary
| | - Eva Leiter
- University of Debrecen, Faculty of Science and Technology, Department of Biotechnology and Microbiology, Debrecen, Hungary
| | - Sandor Biro
- University of Debrecen, Faculty of Medicine, Department of Human Genetics, Debrecen, Hungary
| | - Melinda Paholcsek
- University of Debrecen, Faculty of Medicine, Department of Human Genetics, Debrecen, Hungary
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23
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Morton CO, White PL, Barnes RA, Klingspor L, Cuenca-Estrella M, Lagrou K, Bretagne S, Melchers W, Mengoli C, Caliendo AM, Cogliati M, Debets-Ossenkopp Y, Gorton R, Hagen F, Halliday C, Hamal P, Harvey-Wood K, Jaton K, Johnson G, Kidd S, Lengerova M, Lass-Florl C, Linton C, Millon L, Morrissey CO, Paholcsek M, Talento AF, Ruhnke M, Willinger B, Donnelly JP, Loeffler J. Determining the analytical specificity of PCR-based assays for the diagnosis of IA: What is Aspergillus? Med Mycol 2018; 55:402-413. [PMID: 28339744 DOI: 10.1093/mmy/myw093] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 09/27/2016] [Indexed: 11/14/2022] Open
Abstract
A wide array of PCR tests has been developed to aid the diagnosis of invasive aspergillosis (IA), providing technical diversity but limiting standardisation and acceptance. Methodological recommendations for testing blood samples using PCR exist, based on achieving optimal assay sensitivity to help exclude IA. Conversely, when testing more invasive samples (BAL, biopsy, CSF) emphasis is placed on confirming disease, so analytical specificity is paramount. This multicenter study examined the analytical specificity of PCR methods for detecting IA by blind testing a panel of DNA extracted from a various fungal species to explore the range of Aspergillus species that could be detected, but also potential cross reactivity with other fungal species. Positivity rates were calculated and regression analysis was performed to determine any associations between technical specifications and performance. The accuracy of Aspergillus genus specific assays was 71.8%, significantly greater (P < .0001) than assays specific for individual Aspergillus species (47.2%). For genus specific assays the most often missed species were A. lentulus (25.0%), A. versicolor (24.1%), A. terreus (16.1%), A. flavus (15.2%), A. niger (13.4%), and A. fumigatus (6.2%). There was a significant positive association between accuracy and using an Aspergillus genus PCR assay targeting the rRNA genes (P = .0011). Conversely, there was a significant association between rRNA PCR targets and false positivity (P = .0032). To conclude current Aspergillus PCR assays are better suited for detecting A. fumigatus, with inferior detection of most other Aspergillus species. The use of an Aspergillus genus specific PCR assay targeting the rRNA genes is preferential.
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Affiliation(s)
| | | | | | | | | | - Katrien Lagrou
- University Hospitals Leuven, Department of Laboratory Medicine and National Reference Center for Mycosis, Leuven, Belgium, Belgium
| | - Stéphane Bretagne
- Paris Diderot, Sorbonne Paris Cité University, Faculty of Medicine, Paris, France
| | | | | | - Angela M Caliendo
- Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island and Aspergillus Technology Consortium, USA
| | - Massimo Cogliati
- Dip. Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy
| | | | | | - Ferry Hagen
- Canisius-Wilhelmina Hospital, Nijmegen. The Netherlands
| | - Catriona Halliday
- Clinical Mycology Reference Laboratory, Pathology West, Westmead, Australia
| | - Petr Hamal
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
| | | | - Katia Jaton
- Institute of Microbiology, University Hospital of Lausanne, Switzerland
| | - Gemma Johnson
- Blizard Institute of Cell and Molecular Science, Queen Mary University of London, London, United Kingdom
| | - Sarah Kidd
- National Mycology Reference Centre, SA Pathology, Adelaide. Australia
| | - Martina Lengerova
- Department of Internal Medicine - Hematology and Oncology, University Hospital Brno, Brno, Czech Republic
| | | | - Chris Linton
- UK Mycology Reference Lab, Public Health England, Bristol, United Kingdom
| | - Laurence Millon
- Laboratoire de Parasitologie-Mycologie Centre Hospitalier Universitaire, Besançon, France
| | | | - Melinda Paholcsek
- University of Debrecen Medical and Health Science Center, Debrecen. Hungary
| | - Alida Fe Talento
- Department of Clinical Microbiology, Trinity College, Dublin, Ireland
| | - Markus Ruhnke
- Charité Medical School, University of Berlin, Berlin. Germany
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24
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Challenges and Solution of Invasive Aspergillosis in Non-neutropenic Patients: A Review. Infect Dis Ther 2017; 7:17-27. [PMID: 29273978 PMCID: PMC5840102 DOI: 10.1007/s40121-017-0183-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 12/31/2022] Open
Abstract
Invasive aspergillosis (IA) is a serious opportunistic infection, which has increasingly been recognized as an emerging disease of non-neutropenic patients. In this group of patients, the diagnosis of IA can be challenging owing to the lack of specificity of symptoms, the difficulty in discriminating colonization from infection, and the lower sensitivity of microbiological and radiological tests compared with immunocompromised patients. The aim of this article is to present to clinicians a critical review on the management of IA in non-neutropenic patients.
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25
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Lamoth F, Calandra T. Early diagnosis of invasive mould infections and disease. J Antimicrob Chemother 2017; 72:i19-i28. [PMID: 28355464 DOI: 10.1093/jac/dkx030] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Invasive mould infections (IMIs), such as invasive aspergillosis or mucormycosis, are a major cause of death in patients with haematological cancer and in patients receiving long-term immunosuppressive therapy. Early diagnosis and prompt initiation of antifungal therapy are crucial steps in the management of patients with IMI. The diagnosis of IMI remains a major challenge, with an increased spectrum of fungal pathogens and a diversity of clinical and radiological presentations within the expanding spectrum of immunocompromised hosts. Diagnosis is difficult to establish and is expressed on a scale of probability (proven, probable and possible). Imaging (CT scan), microbiological tools (direct examination, culture, PCR, fungal biomarkers) and histopathology are the pillars of the diagnostic work-up of IMI. None of the currently available diagnostic tests provides sufficient sensitivity and specificity alone, so the optimal approach relies on a combination of multiple diagnostic strategies, including imaging, fungal biomarkers (galactomannan and 1,3-β-d-glucan) and molecular tools. In recent years, the development of PCR for filamentous fungi (primarily Aspergillus or Mucorales) and the progress made in the standardization of fungal PCR technology, may lead to future advances in the field. The appropriate diagnostic approach for IMI should be individualized to each centre, taking into account the local epidemiology of IMI and the availability of diagnostic tests.
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Affiliation(s)
- Frédéric Lamoth
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.,Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Thierry Calandra
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
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Mercier T, Maertens J. Clinical considerations in the early treatment of invasive mould infections and disease. J Antimicrob Chemother 2017; 72:i29-i38. [PMID: 28355465 DOI: 10.1093/jac/dkx031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Different therapeutic strategies for invasive fungal diseases have been explored, each with particular strengths and weaknesses. Broad-spectrum antifungal prophylaxis seems logical, but selective use is important due to its substantial disadvantages, including interference with diagnostic assays, selection for resistance, drug toxicity and drug-drug interactions. Antimould prophylaxis should be restricted to high-risk groups, such as patients undergoing intensive chemotherapy for acute myeloid leukaemia or myelodysplastic syndrome, allogeneic HSCT patients with prior invasive fungal infection, graft-versus-host-disease or extended neutropenia, recipients of a solid organ transplant, or patients with a high-risk inherited immunodeficiency. An empirical approach, whereby mould-active therapy is started in neutropenic patients with fever unresponsive to broad-spectrum antibiotics, is widely applied but incurs the clinical and cost penalties associated with overtreatment. A benefit for all-cause mortality using empirical therapy has not been shown, but it is recommended for high-risk patients who remain febrile after 4-7 days of broad-spectrum antibiotics and in whom extended neutropenia is anticipated. There is growing interest in delaying antifungal treatment until an invasive fungal infection is confirmed ('pre-emptive' or 'diagnostics-driven' management), prompted by the development of more sensitive diagnostic techniques. Comparisons of empirical versus pre-emptive regimens are sparse, particularly with modern triazole agents, but treatment costs are lower with pre-emptive therapy and the available evidence has not indicated reduced efficacy. Pre-emptive treatment may be appropriate in neutropenic patients who remain febrile after administration of broad-spectrum antibiotics but who are clinically stable. Further work is required to define accurately the specific patient subgroups in which each management approach is optimal.
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Maertens JA, Blennow O, Duarte RF, Muñoz P. The current management landscape: aspergillosis. J Antimicrob Chemother 2017; 71:ii23-ii29. [PMID: 27880666 DOI: 10.1093/jac/dkw393] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Diagnosing invasive aspergillosis (IA) has long been challenging due to the inability to culture the causal Aspergillus agent from blood or other body fluids. This shortcoming has fuelled an interest in non-culture-based diagnostic techniques such as the detection of galactomannan (GM) in blood and bronchoalveolar lavage fluid, the detection of 1,3-β-d-glucan (BDG) in blood and the detection of Aspergillus DNA by PCR-based techniques. Past decades have witnessed important improvements in our understanding of the strengths and limitations of antigen assays and in the standardization of PCR-based DNA techniques. These assays are now being incorporated into care pathways and diagnostic algorithms; they help us to steward and monitor antifungal therapies and to predict treatment outcomes.
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Affiliation(s)
- Johan A Maertens
- University Hospitals Leuven, Campus Gasthuisberg, Leuven, Belgium
| | - Ola Blennow
- Unit of Infectious Diseases, Department of Medicine Huddinge, Karolinska Institutet, and Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Rafael F Duarte
- Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain
| | - Patricia Muñoz
- Clinical Microbiology and Infectious Disease Division, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Hospital Gregorio Marañón, Madrid, Spain.,CIBER Enfermedades Respiratorias-CIBERES (CB06/06/0058), Madrid, Spain.,Medicine Department, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain
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Analytical and Clinical Evaluation of the PathoNostics AsperGenius Assay for Detection of Invasive Aspergillosis and Resistance to Azole Antifungal Drugs Directly from Plasma Samples. J Clin Microbiol 2017; 55:2356-2366. [PMID: 28515217 DOI: 10.1128/jcm.00411-17] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/09/2017] [Indexed: 11/20/2022] Open
Abstract
With the proposal to include Aspergillus PCR in the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions for fungal disease, commercially manufactured assays may be required to provide standardization and accessibility. The PathoNostics AsperGenius assay represents one such test that has the ability to detect a range of Aspergillus species as well as azole resistance in Aspergillus fumigatus Its performance has been validated on bronchoalveolar lavage (BAL) fluid and serum specimens, but recent evidence suggests that testing of plasma may have enhanced sensitivity over that with serum. We decided to evaluate the analytical and clinical performances of the PathoNostics AsperGenius assay for testing of plasma. For the analytical evaluations, plasma was spiked with various concentrations of Aspergillus genomic DNA before extraction following international recommendations, using two automated platforms. For the clinical study, 211 samples from 10 proven/probable invasive aspergillosis (IA) and 2 possible IA cases and 27 controls were tested. The limits of detection for testing of DNA extracted using the bioMérieux EasyMag and Qiagen EZ1 extractors were 5 and 10 genomes/0.5-ml sample, respectively. In the clinical study, true positivity was significantly greater than false positivity (P < 0.0001). The sensitivity and specificity obtained using a single positive result as significant were 80% and 77.8%, respectively. If multiple samples were required to be positive, specificity was increased to 100%, albeit sensitivity was reduced to 50%. The AsperGenius assay provided good clinical performance, but the predicted improvement of testing with plasma was not seen, possibly as a result of target degradation attributed to sample storage. Prospective testing is required to determine the clinical utility of this assay, particularly for the diagnosis of azole-resistant disease.
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Abstract
PCR-based detection of fungal pathogens offers a sensitive and specific tool for the diagnosis of invasive fungal infections. A large variety of different clinical specimen types can be used as original material. However, certain precautions, in addition to the published MIQE guidelines [1], need to be taken to prevent contaminations from airborne fungal spores and PCR reagents. In addition, the European Aspergillus PCR Initiative (EAPCRI) recently defined standards for Aspergillus PCR [2, 3], following these recommendations leads to superior sensitivity. The combination of fungal PCR with the galactomannan ELISA assay increases the sensitivity for the detection of Aspergillus DNA from blood, compared to a single assay only [4, 5].
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Affiliation(s)
- Jan Springer
- Medizinische Klinik II, Universitätklinikum Würzburg, Josef-Schneider-Str. 2, Würzburg, 97080, Germany
| | - Jürgen Löffler
- Medizinische Klinik II, Universitätklinikum Würzburg, Josef-Schneider-Str. 2, Würzburg, 97080, Germany.
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Abstract
PCR can aid in the diagnosis of invasive fungal disease (IFD). While the large number of "in-house" methodologies drives technological diversity, providing robustness, they make it difficult to identify optimal strategies, limiting standardization, and widespread acceptance. No matter how efficient, PCR utility will be limited by the quality of extracted nucleic acid. This chapter highlights benefits and limitations affecting the nucleic acid extraction process, before focusing on recent recommendations that through multicenter evaluation have provided optimal and standardized methodology.
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Affiliation(s)
- P Lewis White
- Public Health Wales Microbiology Cardiff, University Hospital of Wales, Heath Park, Cardiff, CF14 4XW, UK.
| | - Rosemary A Barnes
- Public Health Wales Microbiology Cardiff, University Hospital of Wales, Heath Park, Cardiff, CF14 4XW, UK.,Department of Infection and Immunity, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
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Rahn S, Schuck A, Kondakci M, Haas R, Neuhausen N, Pfeffer K, Henrich B. A novel comprehensive set of fungal Real time PCR assays (fuPCR) for the detection of fungi in immunocompromised haematological patients—A pilot study. Int J Med Microbiol 2016; 306:611-623. [DOI: 10.1016/j.ijmm.2016.10.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 10/12/2016] [Indexed: 01/04/2023] Open
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Barnes RA, White PL. PCR Technology for Detection of Invasive Aspergillosis. J Fungi (Basel) 2016; 2:jof2030023. [PMID: 29376940 PMCID: PMC5753136 DOI: 10.3390/jof2030023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/20/2016] [Accepted: 07/26/2016] [Indexed: 11/16/2022] Open
Abstract
The application of molecular technologies to aid diagnosis and management of infectious diseases has had a major impact and many assays are in routine use. Diagnosis of aspergillosis has lagged behind. Lack of standardization and limited commercial interest have meant that PCR was not included in consensus diagnostic criteria for invasive fungal disease. In the last ten years careful evaluation and validation by the Aspergillus European PCR initiative with the development of standardized extraction, amplification and detection protocols for various specimen types, has provided the opportunity for clinical utility to be investigated. PCR has the potential to not only exclude a diagnosis of invasive aspergillosis but in combination with antigen testing may offer an approach for the early diagnosis and treatment of invasive aspergillosis in high-risk populations, with the added benefit of detection of genetic markers associated with antifungal resistance.
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Affiliation(s)
- Rosemary A Barnes
- Department of Medical Microbiology and Infectious Diseases, Cardiff University School of Medicine, Cardiff CF14 4XN, UK.
| | - P Lewis White
- Public Health Wales Microbiology, Cardiff CF14 4 XW, UK.
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Bernal-Martínez L, Alastruey-Izquierdo A, Cuenca-Estrella M. Diagnostics and susceptibility testing in Aspergillus. Future Microbiol 2016; 11:315-28. [PMID: 26848512 DOI: 10.2217/fmb.15.140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Invasive aspergillosis is a major cause of morbidity and mortality in immunosuppressed patients. Early diagnosis and correct antifungal treatment have a direct impact on patient survival. A number of newer diagnostic procedures have been developed as alternatives to conventional microbiological methods. The detection of fungal components, largely antigens and DNA, are used in clinical laboratories to diagnose invasive aspergillosis. Other rapid diagnostic tests have been recently developed with promising results. However, antifungal resistance is becoming an emerging problem. The detection of this resistance is important to administer the proper antifungal agent. This text reviews the novelties on new diagnostics Aspergillus spp. PROCEDURES Intrinsic antifungal resistance and mechanisms of secondary resistance to triazoles in A. fumigatus are also reviewed.
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Affiliation(s)
- Leticia Bernal-Martínez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain; Spanish Network for the Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Alastruey-Izquierdo
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain; Spanish Network for the Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
| | - Manuel Cuenca-Estrella
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain; Spanish Network for the Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
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Comparison of Nonculture Blood-Based Tests for Diagnosing Invasive Aspergillosis in an Animal Model. J Clin Microbiol 2016; 54:960-6. [PMID: 26791366 PMCID: PMC4809952 DOI: 10.1128/jcm.03233-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 01/13/2016] [Indexed: 11/20/2022] Open
Abstract
The European Aspergillus PCR Initiative (EAPCRI) has provided recommendations for the PCR testing of whole blood (WB) and serum/plasma. It is important to test these recommended protocols on nonsimulated “in vivo” specimens before full clinical evaluation. The testing of an animal model of invasive aspergillosis (IA) overcomes the low incidence of disease and provides experimental design and control that is not possible in the clinical setting. Inadequate performance of the recommended protocols at this stage would require reassessment of methods before clinical trials are performed and utility assessed. The manuscript describes the performance of EAPCRI protocols in an animal model of invasive aspergillosis. Blood samples taken from a guinea pig model of IA were used for WB and serum PCR. Galactomannan and β-d-glucan detection were evaluated, with particular focus on the timing of positivity and on the interpretation of combination testing. The overall sensitivities for WB PCR, serum PCR, galactomannan, and β-d-glucan were 73%, 65%, 68%, and 46%, respectively. The corresponding specificities were 92%, 79%, 80%, and 100%, respectively. PCR provided the earliest indicator of IA, and increasing galactomannan and β-d-glucan values were indicators of disease progression. The combination of WB PCR with galactomannan and β-d-glucan proved optimal (area under the curve [AUC], 0.95), and IA was confidently diagnosed or excluded. The EAPRCI-recommended PCR protocols provide performance comparable to commercial antigen tests, and clinical trials are warranted. By combining multiple tests, IA can be excluded or confirmed, highlighting the need for a combined diagnostic strategy. However, this approach must be balanced against the practicality and cost of using multiple tests.
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Comparison of Performance Characteristics of Aspergillus PCR in Testing a Range of Blood-Based Samples in Accordance with International Methodological Recommendations. J Clin Microbiol 2016; 54:705-11. [PMID: 26739157 DOI: 10.1128/jcm.02814-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/30/2015] [Indexed: 01/26/2023] Open
Abstract
Standardized methodologies for the molecular detection of invasive aspergillosis (IA) have been established by the European Aspergillus PCR Initiative for the testing of whole blood, serum, and plasma. While some comparison of the performance of Aspergillus PCR when testing these different sample types has been performed, no single study has evaluated all three using the recommended protocols. Standardized Aspergillus PCR was performed on 423 whole-blood pellets (WBP), 583 plasma samples, and 419 serum samples obtained from hematology patients according to the recommendations. This analysis formed a bicenter retrospective anonymous case-control study, with diagnosis according to the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus definitions (11 probable cases and 36 controls). Values for clinical performance using individual and combined samples were calculated. For all samples, PCR positivity was significantly associated with cases of IA (for plasma, P = 0.0019; for serum, P = 0.0049; and for WBP, P = 0.0089). Plasma PCR generated the highest sensitivity (91%); the sensitivities for serum and WBP PCR were 80% and 55%, respectively. The highest specificity was achieved when testing WBP (96%), which was significantly superior to the specificities achieved when testing serum (69%, P = 0.0238) and plasma (53%, P = 0.0002). No cases were PCR negative in all specimen types, and no controls were PCR positive in all specimens. This study confirms that Aspergillus PCR testing of plasma provides robust performance while utilizing commercial automated DNA extraction processes. Combining PCR testing of different blood fractions allows IA to be both confidently diagnosed and excluded. A requirement for multiple PCR-positive plasma samples provides similar diagnostic utility and is technically less demanding. Time to diagnosis may be enhanced by testing multiple contemporaneously obtained sample types.
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Sanguinetti M, Posteraro B. Diagnostic of Fungal Infections Related to Biofilms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 931:63-82. [PMID: 27300347 DOI: 10.1007/5584_2016_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Fungal biofilm-related infections, most notably those caused by the Candida and Aspergillus genera, need to be diagnosed accurately and rapidly to avoid often unfavorable outcomes. Despite diagnosis of these infections is still based on the traditional histopathology and culture, the use of newer, rapid methods has enormously enhanced the diagnostic capability of a modern clinical mycology laboratory. Thus, while accurate species-level identification of fungal isolates can be achieved with turnaround times considerably shortened, nucleic acid-based or antigen-based detection methods can be considered useful adjuncts for the diagnosis of invasive forms of candidiasis and aspergillosis. Furthermore, simple, reproducible, and fast methods have been developed to quantify biofilm production by fungal isolates in vitro. In this end, isolates can be categorized as low, moderate, or high biofilm-forming, and this categorization may reflect their differential response to the conventional antifungal therapy. By means of drug susceptibility testing performed on fungal biofilm-growing isolates, it is now possible to evaluate not only the activity of conventional antifungal agents, but also of novel anti-biofilm agents. Despite this, future diagnostic methods need to target specific biofilm components/molecules, in order to provide a direct proof of the presence of this growth phenotype on the site of infection. In the meantime, our knowledge of the processes underlying the adaptive drug resistance within the biofilm has put into evidence biofilm-specific molecules that could be potentially helpful as therapeutic targets. Surely, the successful management of clinically relevant fungal biofilms will rely upon the advancement and/or refinement of these approaches.
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Affiliation(s)
| | - Brunella Posteraro
- Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Rome, Italy
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Clinical Performance of Aspergillus PCR for Testing Serum and Plasma: a Study by the European Aspergillus PCR Initiative. J Clin Microbiol 2015; 53:2832-7. [PMID: 26085618 PMCID: PMC4540904 DOI: 10.1128/jcm.00905-15] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/12/2015] [Indexed: 12/19/2022] Open
Abstract
Aspergillus PCR testing of serum provides technical simplicity but with potentially reduced sensitivity compared to whole-blood testing. With diseases for which screening to exclude disease represents an optimal strategy, sensitivity is paramount. The associated analytical study confirmed that DNA concentrations were greater in plasma than those in serum. The aim of the current investigation was to confirm analytical findings by comparing the performance of Aspergillus PCR testing of plasma and serum in the clinical setting. Standardized Aspergillus PCR was performed on plasma and serum samples concurrently obtained from hematology patients in a multicenter retrospective anonymous case-control study, with cases diagnosed according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus definitions (19 proven/probable cases and 42 controls). Clinical performance and clinical utility (time to positivity) were calculated for both kinds of samples. The sensitivity and specificity for Aspergillus PCR when testing serum were 68.4% and 76.2%, respectively, and for plasma, they were 94.7% and 83.3%, respectively. Eighty-five percent of serum and plasma PCR results were concordant. On average, plasma PCR was positive 16.8 days before diagnosis and was the earliest indicator of infection in 13 cases, combined with other biomarkers in five cases. On average, serum PCR was positive 10.8 days before diagnosis and was the earliest indicator of infection in six cases, combined with other biomarkers in three cases. These results confirm the analytical finding that the sensitivity of Aspergillus PCR using plasma is superior to that using serum. PCR positivity occurs earlier when testing plasma and provides sufficient sensitivity for the screening of invasive aspergillosis while maintaining methodological simplicity.
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