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Choudhary H, Kaur H, Singh S, Singh R, Muthu V, Verma R, Rudramurthy SM, Agarwal R, Jain S, Bal A, Ghosh AK, Chakrabarti A. A novel indirect ELISA for serodiagnosis of mucormycosis using antigens from Rhizopus arrhizus. Mycoses 2024; 67:e13730. [PMID: 38712824 DOI: 10.1111/myc.13730] [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: 02/26/2024] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND Due to a delay in diagnosis by conventional techniques and high mortality, the development of a standardised and rapid non-culture-based technique is an unmet need in pulmonary, gastrointestinal, and disseminated forms of mucormycosis. Though limited studies have been conducted for molecular diagnosis, there are no established serologic tests for this highly fatal infection. OBJECTIVE To develop and evaluate an indirect in-house enzyme-linked immunosorbent assay (ELISA) utilising antigens of Rhizopus arrhizus for detecting anti-Rhizopus antibodies (IgG and IgM) in sera of patients with mucormycosis. METHODS We extracted both secretory and mycelial Rhizopus antigens using standardised protocols. Bradford assay was used for protein quantification. We then standardised an indirect ELISA using R. arrhizus mycelial and secretory antigens (10.0 μg/mL in bicarbonate buffer pH 9.2) for detecting anti-Rhizopus IgG and IgM antibodies in patient sera. We included patients with mucormycosis, other fungal infections, and healthy controls. Antibody index value (E-value) was calculated for each patient sample. RESULTS Asparagine broth culture filtrate utilising 85% ammonium sulphate salt fractionation and mycelial homogenate grown in yeast extract peptone dextrose (YPD) broth precipitated with trichloroacetic acid (TCA) yielded a large amount of good-quality protein for the assay. We included 55 patients with mucormycosis (rhino-orbito-cerebral mucormycosis [ROCM, n = 39], pulmonary [n = 15], gastrointestinal [n = 1]), 24 with other fungal infections (probable aspergillosis [n = 14], candidiasis [n = 10]), and healthy controls (n = 16). The sensitivity of the antibody test for diagnosing mucormycosis ranged from 83.6-92.7% for IgG and 72.7-87.3% for IgM, with a specificity of 91.7-92.5% for IgG and 80-82.5% for IgM. The sera from patients with other fungal infections and healthy individuals did not show significant cross-reactivity. CONCLUSION The detection of anti-Rhizopus IgG antibody performed significantly better in comparison to IgM-based ELISA for diagnosing both ROCM (sensitivity of 84.6% vs. 69.2%) and pulmonary cases (86.6% vs. 80.0%). More extensive studies are required to confirm our findings.
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Affiliation(s)
| | - Harsimran Kaur
- Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Shreya Singh
- Department of Medical Microbiology, Dr. B. R. Ambedkar Institute of Medical Sciences, Mohali, Punjab, India
| | - Rachna Singh
- Department of Microbial Biotechnology, Panjab University, Chandigarh, India
| | - Valliappan Muthu
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Roshan Verma
- Department of Otolaryngology (ENT), Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Shivaprakash M Rudramurthy
- Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Ritesh Agarwal
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Sanjay Jain
- Department of Internal Medicine, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Amanjit Bal
- Department of Histopathology, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
| | - Anup K Ghosh
- Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India
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Davies GE, Thornton CR. A Lateral-Flow Device for the Rapid Detection of Scedosporium Species. Diagnostics (Basel) 2024; 14:847. [PMID: 38667492 PMCID: PMC11048963 DOI: 10.3390/diagnostics14080847] [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: 03/26/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Scedosporium species are human pathogenic fungi, responsible for chronic, localised, and life-threatening disseminated infections in both immunocompetent and immunocompromised individuals. The diagnosis of Scedosporium infections currently relies on non-specific CT, lengthy and insensitive culture from invasive biopsy, and the time-consuming histopathology of tissue samples. At present, there are no rapid antigen tests that detect Scedosporium-specific biomarkers. Here, we report the development of a rapid (30 min) and sensitive (pmol/L sensitivity) lateral-flow device (LFD) test, incorporating a Scedosporium-specific IgG1 monoclonal antibody (mAb), HG12, which binds to extracellular polysaccharide (EPS) antigens between ~15 kDa and 250 kDa secreted during the hyphal growth of the pathogens. The test is compatible with human serum and allows for the detection of the Scedosporium species most frequently reported as agents of human disease (Scedosporium apiospermum, Scedosporium aurantiacum, and Scedosporium boydii), with limits of detection (LODs) of the EPS biomarkers in human serum of ~0.81 ng/mL (S. apiospermum), ~0.94 ng/mL (S. aurantiacum), and ~1.95 ng/mL (S. boydii). The Scedosporium-specific LFD (ScedLFD) test therefore provides a potential novel opportunity for the detection of infections caused by different Scedosporium species.
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Affiliation(s)
- Genna E. Davies
- ISCA Diagnostics Ltd., B12A, Hatherly Laboratories, Prince of Wales Road, Exeter EX4 4PS, UK;
| | - Christopher R. Thornton
- ISCA Diagnostics Ltd., B12A, Hatherly Laboratories, Prince of Wales Road, Exeter EX4 4PS, UK;
- Biosciences, Faculty of Health and Life Sciences, Prince of Wales Road, Exeter EX4 4PS, UK
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Schmidt C. Fungal diseases are spreading undetected. Nature 2024:10.1038/d41586-024-00751-z. [PMID: 38485825 DOI: 10.1038/d41586-024-00751-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
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Thornton CR. The potential for rapid antigen testing for mucormycosis in the context of COVID-19. Expert Rev Mol Diagn 2024; 24:161-167. [PMID: 37405409 DOI: 10.1080/14737159.2023.2233906] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/04/2023] [Indexed: 07/06/2023]
Abstract
INTRODUCTION Mucormycosis is a highly aggressive angio-invasive disease of humans caused by Mucorales fungi. Prior to the COVID-19 pandemic, mucormycosis was a rare mycosis typically seen in immunocompromised patients with hematological malignancies or in transplant recipients. During the second wave of the pandemic, there was a dramatic increase in the disease, especially in India where a unique set of circumstances led to large numbers of life-threatening and disfiguring rhino-orbital-cerebral mucormycosis (ROCM) infections. AREAS COVERED The review examines mucormycosis as a super-infection of COVID-19 patients, and the risk factors for COVID-19-associated mucormycosis (CAM) that drove the ROCM epidemic in India. The limitations of current diagnostic procedures are identified, and the measures needed to improve the speed and accuracy of detection discussed. EXPERT OPINION Despite increased awareness, global healthcare systems remain unprepared for further outbreaks of ROCM. Current diagnosis of the disease is slow and inaccurate, negatively impacting on patient survival. This is most evident in low- to middle-income countries which lack suitably equipped diagnostic facilities for rapid identification of the infecting pathogens. Rapid antigen testing using point-of-care lateral-flow assays could potentially have aided in the quick and accurate diagnosis of the disease, allowing earlier intervention with surgery and Mucorales-active antifungal drugs.
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Thornton CR, Davies GE, Dougherty L. Development of a monoclonal antibody and a lateral-flow device for the rapid detection of a Mucorales-specific biomarker. Front Cell Infect Microbiol 2023; 13:1305662. [PMID: 38145040 PMCID: PMC10739493 DOI: 10.3389/fcimb.2023.1305662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
Mucoromycosis is a highly aggressive angio-invasive disease of humans caused by fungi in the zygomycete order, Mucorales. While Rhizopus arrhizus is the principal agent of mucoromycosis, other Mucorales fungi including Apophysomyces, Cunninghamella, Lichtheimia, Mucor, Rhizomucor and Syncephalastrum are able to cause life-threatening rhino-orbital-cerebral, pulmonary, gastro-intestinal and necrotising cutaneous infections in humans. Diagnosis of the disease currently relies on non-specific CT, lengthy and insensitive culture from invasive biopsy, and time-consuming histopathology of tissue samples. At present, there are no rapid antigen tests that detect Mucorales-specific biomarkers of infection, and which allow point-of-care diagnosis of mucoromycosis. Here, we report the development of an IgG2b monoclonal antibody (mAb), TG11, which binds to extracellular polysaccharide (EPS) antigens of between 20 kDa and 250 kDa secreted during hyphal growth of Mucorales fungi. The mAb is Mucorales-specific and does not cross-react with other yeasts and molds of clinical importance including Aspergillus, Candida, Cryptococcus, Fusarium, Lomentospora and Scedosporium species. Using the mAb, we have developed a Competitive lateral-flow device that allows rapid (30 min) detection of the EPS biomarker in human serum and bronchoalveolar lavage (BAL), with a limit of detection (LOD) in human serum of ~100 ng/mL serum (~224.7 pmol/L serum). The LFD therefore provides a potential novel opportunity for detection of mucoromycosis caused by different Mucorales species.
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Affiliation(s)
- Christopher R. Thornton
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- ISCA Diagnostics Ltd., Hatherly Laboratories, Exeter, United Kingdom
| | - Genna E. Davies
- ISCA Diagnostics Ltd., Hatherly Laboratories, Exeter, United Kingdom
| | - Laura Dougherty
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
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Thompson GR, Jenks JD, Baddley JW, Lewis JS, Egger M, Schwartz IS, Boyer J, Patterson TF, Chen SCA, Pappas PG, Hoenigl M. Fungal Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management. Clin Microbiol Rev 2023; 36:e0001923. [PMID: 37439685 PMCID: PMC10512793 DOI: 10.1128/cmr.00019-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023] Open
Abstract
Fungal endocarditis accounts for 1% to 3% of all infective endocarditis cases, is associated with high morbidity and mortality (>70%), and presents numerous challenges during clinical care. Candida spp. are the most common causes of fungal endocarditis, implicated in over 50% of cases, followed by Aspergillus and Histoplasma spp. Important risk factors for fungal endocarditis include prosthetic valves, prior heart surgery, and injection drug use. The signs and symptoms of fungal endocarditis are nonspecific, and a high degree of clinical suspicion coupled with the judicious use of diagnostic tests is required for diagnosis. In addition to microbiological diagnostics (e.g., blood culture for Candida spp. or galactomannan testing and PCR for Aspergillus spp.), echocardiography remains critical for evaluation of potential infective endocarditis, although radionuclide imaging modalities such as 18F-fluorodeoxyglucose positron emission tomography/computed tomography are increasingly being used. A multimodal treatment approach is necessary: surgery is usually required and should be accompanied by long-term systemic antifungal therapy, such as echinocandin therapy for Candida endocarditis or voriconazole therapy for Aspergillus endocarditis.
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Affiliation(s)
- George R. Thompson
- Department of Internal Medicine, Division of Infectious Diseases, University of California-Davis Medical Center, Sacramento, California, USA
- Department of Medical Microbiology and Immunology, University of California-Davis, Davis, California, USA
| | - 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
| | - John W. Baddley
- Department of Medicine, Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - James S. Lewis
- Department of Pharmacy, Oregon Health & Science University, Portland, Oregon, USA
| | - Matthias Egger
- Division of Infectious Diseases, ECMM Excellence Center for Medical Mycology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Ilan S. Schwartz
- Division of Infectious Diseases, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Johannes Boyer
- Division of Infectious Diseases, ECMM Excellence Center for Medical Mycology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Thomas F. Patterson
- Department of Medicine, Division of Infectious Diseases, The University of Texas Health Science Center, San Antonio, Texas, USA
| | - Sharon C.-A. Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Sydney, New South Wales, Australia
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, The University of Sydney, Sydney, New South Wales, Australia
| | - Peter G. Pappas
- Department of Medicine Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Martin Hoenigl
- Division of Infectious Diseases, ECMM Excellence Center for Medical Mycology, Department of Medicine, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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Lamoth F. Novel Approaches in the Management of Mucormycosis. CURRENT FUNGAL INFECTION REPORTS 2023; 17:1-10. [PMID: 37360854 PMCID: PMC10165581 DOI: 10.1007/s12281-023-00463-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2023] [Indexed: 06/28/2023]
Abstract
Purpose of Review Invasive mucormycosis (IM), caused by fungi of the order Mucorales, is one of the deadliest fungal infection among hematologic cancer patients. Its incidence is also increasingly reported in immunocompetent individuals, notably with the COVID-19 pandemic. Therefore, there is an urgent need for novel diagnostic and therapeutic approaches of IM. This review discusses the current advances in this field. Recent Findings Early diagnosis of IM is crucial and can be improved by Mucorales-specific PCR and development of lateral-flow immunoassays for specific antigen detection. The spore coat proteins (CotH) are essential for virulence of the Mucorales and may represent a target for novel antifungal therapies. Adjuvant therapies boosting the immune response, such as interferon-γ, anti-PDR1 or fungal-specific chimeric antigen receptor (CAR) T-cells, are also considered. Summary The most promising perspectives for improved management of IM consist of a multilayered approach targeting both the pathogen and the host immune system.
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Affiliation(s)
- Frederic Lamoth
- Service of Infectious Diseases, Department of Medicine, Lausanne University Hospital, University of Lausanne, Rue du Bugnon 48, 1011 Lausanne, Switzerland
- Institute of Microbiology, Department of Laboratory Medicine and Pathology, Lausanne University Hospital, University of Lausanne, Rue du Bugnon 48, 1011 Lausanne, Switzerland
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White PL. Developments in Fungal Serology. CURRENT FUNGAL INFECTION REPORTS 2023; 17:1-12. [PMID: 37360856 PMCID: PMC10099008 DOI: 10.1007/s12281-023-00462-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2023] [Indexed: 06/28/2023]
Abstract
Purpose of Review The true incidence of fungal disease is hampered by conventionally poor diagnostic tests, limited access to advanced diagnostics, and limited surveillance. The availability of serological testing has been available for over two decades and generally underpins the modern diagnosis of the most common forms of fungal disease. This review will focus on technical developments of serological tests for the diagnosis of fungal disease, describing advances in clinical performance when available. Recent Findings Despite their longevity, technical, clinical, and performance limitations remain, and tests specific for fungal pathogens outside the main pathogens are lacking. The availability of LFA and automated systems, capable of running multiple different tests, represents significant developments, but clinical performance data is variable and limited. Summary Fungal serology has significantly advanced the diagnosis of the main fungal infections, with LFA availability increasing accessibility to testing. Combination testing has the potential to overcome performance limitations.
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Affiliation(s)
- P. Lewis White
- Public Health Wales Mycology Reference Laboratory and Cardiff University Centre for Trials Research/Division of Infection and Immunity, UHW, Heath Park, Cardiff, CF14 4XW UK
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What Is New in Pulmonary Mucormycosis? J Fungi (Basel) 2023; 9:jof9030307. [PMID: 36983475 PMCID: PMC10057210 DOI: 10.3390/jof9030307] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Mucormycosis is a rare but life-threatening fungal infection due to molds of the order Mucorales. The incidence has been increasing over recent decades. Worldwide, pulmonary mucormycosis (PM) presents in the lungs, which are the third main location for the infection after the rhino-orbito-cerebral (ROC) areas and the skin. The main risk factors for PM include hematological malignancies and solid organ transplantation, whereas ROC infections are classically favored by diabetes mellitus. The differences between the ROC and pulmonary locations are possibly explained by the activation of different mammalian receptors—GRP78 in nasal epithelial cells and integrin β1 in alveolar epithelial cells—in response to Mucorales. Alveolar macrophages and neutrophils play a key role in the host defense against Mucorales. The diagnosis of PM relies on CT scans, cultures, PCR tests, and histology. The reversed halo sign is an early, but very suggestive, sign of PM in neutropenic patients. Recently, the serum PCR test showed a very encouraging performance for the diagnosis and follow-up of mucormycosis. Liposomal amphotericin B is the drug of choice for first-line therapy, together with correction of underlying disease and surgery when feasible. After a stable or partial response, the step-down treatment includes oral isavuconazole or posaconazole delayed release tablets until a complete response is achieved. Secondary prophylaxis should be discussed when there is any risk of relapse, such as the persistence of neutropenia or the prolonged use of high-dose immunosuppressive therapy. Despite these novelties, the mortality rate from PM remains higher than 50%. Therefore, future research must define the place for combination therapy and adjunctive treatments, while the development of new treatments is necessary.
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A Multiplex PCR and DNA-Sequencing Workflow on Serum for the Diagnosis and Species Identification for Invasive Aspergillosis and Mucormycosis. J Clin Microbiol 2023; 61:e0140922. [PMID: 36533925 PMCID: PMC9879116 DOI: 10.1128/jcm.01409-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
There has been significant increase in the use of molecular tools for the diagnosis of invasive aspergillosis (IA) and mucormycosis. However, their range of detection may be too limited as species diversity and coinfections are increasing. Here, we aimed to evaluate a molecular workflow based on a new multiplex PCR assay detecting the whole Aspergillus genus and the Mucorales order followed by a species-specific PCR or a DNA-sequencing approach for IA and/or mucormycosis diagnosis and species identification on serum. Performances of the MycoGENIE Aspergillus spp./Mucorales spp. duplex PCR kit were analyzed on a broad range of fungal strains and on sera from high-risk patients prospectively over a 12-month period. The kit allowed the detection of nine Aspergillus species and 10 Mucorales (eight genera) strains assessed. No cross-reactions between the two targets were observed. Sera from 744 patients were prospectively analyzed, including 35 IA, 16 mucormycosis, and four coinfections. Sensitivity varies from 85.7% (18/21) in probable/proven IA to 28.6% (4/14) in COVID-19-associated pulmonary aspergillosis. PCR-positive samples corresponded to 21 A. fumigatus, one A. flavus, and one A. nidulans infections. All the disseminated mucormycosis were positive in serum (14/14), including the four Aspergillus coinfections, but sensitivity fell to 33.3% (2/6) in localized forms. DNA sequencing allowed Mucorales identification in serum in 15 patients. Remarkably, the most frequent species identified was Rhizomucor pusillus (eight cases), whereas it is barely found in fungal culture. This molecular workflow is a promising approach to improve IA and mucormycosis diagnosis and epidemiology.
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Fernández-Cruz A, Magira E. Current Issues in Fungal Infections and COVID-19. J Fungi (Basel) 2022; 8:1115. [PMID: 36354882 PMCID: PMC9693358 DOI: 10.3390/jof8111115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023] Open
Abstract
The COVID-19 pandemic has brought up a new host for fungal invasive infections [...].
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Affiliation(s)
- Ana Fernández-Cruz
- Infectious Diseases Unit, Internal Medicine Department, University Hospital Puerta de Hierro-Majadahonda, Health Research Institute Puerta de Hierro-Segovia de Arana, 28222 Majadahonda, Spain
| | - Eleni Magira
- First Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, National and Kapodistrian University of Athens Medical School, 11527 Athens, Greece
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