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Savers A, Rasid O, Parlato M, Brock M, Jouvion G, Ryffel B, Cavaillon JM, Eberl G, Ibrahim-Granet O. Infection-Mediated Priming of Phagocytes Protects against Lethal Secondary Aspergillus fumigatus Challenge. PLoS One 2016; 11:e0153829. [PMID: 27078879 PMCID: PMC4831689 DOI: 10.1371/journal.pone.0153829] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 04/04/2016] [Indexed: 11/30/2022] Open
Abstract
Phagocytes restrict the germination of Aspergillus fumigatus conidia and prevent the establishment of invasive pulmonary aspergillosis in immunecompetent mice. Here we report that immunecompetent mice recovering from a primary A. fumigatus challenge are protected against a secondary lethal challenge. Using RAGγc knock-out mice we show that this protection is independent of T, B and NK cells. In protected mice, lung phagocytes are recruited more rapidly and are more efficient in conidial phagocytosis and killing. Protection was also associated with an enhanced expression of CXCR2 and Dectin-1 on bone marrow phagocytes. We also show that protective lung cytokine and chemokine responses are induced more rapidly and with enhanced dynamics in protected mice. Our findings support the hypothesis that following a first encounter with a non-lethal dose of A. fumigatus conidia, the innate immune system is primed and can mediate protection against a secondary lethal infection.
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Affiliation(s)
- Amélie Savers
- Institut Pasteur, Unité Cytokines & Inflammation, Paris, France
- Fungal Genetics and Biology, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Orhan Rasid
- Institut Pasteur, Unité Cytokines & Inflammation, Paris, France
| | - Marianna Parlato
- INSERM UMR S1163 -Institut Imagine, Laboratoire d’Immunité Intestinale, Paris, France
| | - Matthias Brock
- Fungal Genetics and Biology, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Gregory Jouvion
- Institut Pasteur, Unité Histopathologie Humaine et Modèles Animaux, Paris, France
| | - Bernhard Ryffel
- INSERM, UMR 7355, Immunologie Moléculaire, Institut de Transgénose, Université d'Orléans et Centre National de la Recherche Scientifique, Orléans, France
| | | | - Gerard Eberl
- Institut Pasteur, Lymphoid Tissue Development Unit, Paris, France
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Abstract
We are presenting a quantitative proteomics tally of the most commonly expressed conserved fungal proteins of the cytosol, the cell wall, and the secretome. It was our goal to identify fungi-typical proteins that do not share significant homology with human proteins. Such fungal proteins are of interest to the development of vaccines or drug targets. Protein samples were derived from 13 fungal species, cultured in rich or in minimal media; these included clinical isolates of Aspergillus, Candida, Mucor, Cryptococcus, and Coccidioides species. Proteomes were analyzed by quantitative MSE (Mass Spectrometry-Elevated Collision Energy). Several thousand proteins were identified and quantified in total across all fractions and culture conditions. The 42 most abundant proteins identified in fungal cell walls or supernatants shared no to very little homology with human proteins. In contrast, all but five of the 50 most abundant cytosolic proteins had human homologs with sequence identity averaging 59%. Proteomic comparisons of the secreted or surface localized fungal proteins highlighted conserved homologs of the Aspergillus fumigatus proteins 1,3-β-glucanosyltransferases (Bgt1, Gel1-4), Crf1, Ecm33, EglC, and others. The fact that Crf1 and Gel1 were previously shown to be promising vaccine candidates, underlines the value of the proteomics data presented here.
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103
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Yazdani MR, Foroughifar E, Mohammadi R. Identification of Candida Species Isolated from Renal Transplant Recipients with Candiduria. Int J Organ Transplant Med 2016; 7:206-211. [PMID: 28078059 PMCID: PMC5219581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND Renal transplantation has long been considered the gold standard medical care for patients with end-stage renal disease. Candiduria continue to be a significant complication for renal transplant recipients. The risk of infections depends on the amount of immunosuppression and exposure to the potential pathogens. OBJECTIVE Molecular identification of Candida species isolated from renal transplant recipients with candiduria. METHODS Between 2009 and 2014, 62 Candida isolates were collected from 485 renal transplant recipients. All isolates were identified by PCR-RFLP profiles after digestion with the restriction enzyme MspI. RESULTS C. albicans (44%) and C. parapsilosis complex (5%) had the most and the least prevalence, respectively. Male to female ratio was 26/36, ranging in age from 19 to 62 years. CONCLUSION Due to the fact that candiduria is connected with increased mortality in renal transplant recipients, precise identification of Candida species by molecular techniques can lead to an appropriate therapy among high risk patients. C. albicans remains the most prevalent species isolated from renal transplant recipients, Nevertheless, the number of non-C. albicans Candida species looks to be emerging.
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Affiliation(s)
- M. R. Yazdani
- Department of Infectious Diseases, Al-Zahra hospital, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - E. Foroughifar
- Department of Infectious Diseases, Al-Zahra hospital, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - R. Mohammadi
- Department of Medical Parasitology and Mycology, School of Medicine, Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran,Correspondence: Rasoul Mohammadi, Assistant Professor, Department of Medical Parasitology and Mycology, School of Medicine, Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran ,Tel: +98-313-792-9004, Fax: +98-313-668-8597, E-mail:
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104
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Phaeohyphomycosis in Transplant Patients. J Fungi (Basel) 2015; 2:jof2010002. [PMID: 29376919 PMCID: PMC5753083 DOI: 10.3390/jof2010002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 12/15/2015] [Accepted: 12/17/2015] [Indexed: 11/17/2022] Open
Abstract
Phaeohyphomycosis is caused by a large, heterogenous group of darkly pigmented fungi. The presence of melanin in their cell walls is characteristic, and is likely an important virulence factor. These infections are being increasingly seen in a variety of clinical syndromes in both immunocompromised and normal individuals. Transplant patients are especially at risk due their prolonged immunosuppression. There are no specific diagnostic tests for these fungi, though the Fontana-Masson stain is relatively specific in tissue. They are generally seen in a worldwide distribution, though a few species are only found in specific geographic regions. Management of these infections is not standardized due to lack of clinical trials, though recommendations are available based on clinical experience from case reports and series and animal models. Superficial infections may be treated without systemic therapy. Central nervous system infections are unique in that they often affect otherwise normal individuals, and are difficult to treat. Disseminated infections carry a high mortality despite aggressive therapy, usually with multiple antifungal drugs. Considerable work is needed to determine optimal diagnostic and treatment strategies for these infections.
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105
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106
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Irmer H, Tarazona S, Sasse C, Olbermann P, Loeffler J, Krappmann S, Conesa A, Braus GH. RNAseq analysis of Aspergillus fumigatus in blood reveals a just wait and see resting stage behavior. BMC Genomics 2015; 16:640. [PMID: 26311470 PMCID: PMC4551469 DOI: 10.1186/s12864-015-1853-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/17/2015] [Indexed: 12/20/2022] Open
Abstract
Background Invasive aspergillosis is started after germination of Aspergillus fumigatus conidia that are inhaled by susceptible individuals. Fungal hyphae can grow in the lung through the epithelial tissue and disseminate hematogenously to invade into other organs. Low fungaemia indicates that fungal elements do not reside in the bloodstream for long. Results We analyzed whether blood represents a hostile environment to which the physiology of A. fumigatus has to adapt. An in vitro model of A. fumigatus infection was established by incubating mycelium in blood. Our model allowed to discern the changes of the gene expression profile of A. fumigatus at various stages of the infection. The majority of described virulence factors that are connected to pulmonary infections appeared not to be activated during the blood phase. Three active processes were identified that presumably help the fungus to survive the blood environment in an advanced phase of the infection: iron homeostasis, secondary metabolism, and the formation of detoxifying enzymes. Conclusions We propose that A. fumigatus is hardly able to propagate in blood. After an early stage of sensing the environment, virtually all uptake mechanisms and energy-consuming metabolic pathways are shut-down. The fungus appears to adapt by trans-differentiation into a resting mycelial stage. This might reflect the harsh conditions in blood where A. fumigatus cannot take up sufficient nutrients to establish self-defense mechanisms combined with significant growth. Electronic supplementary material The online version of this article (doi10.1186/s12864-015-1853-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Henriette Irmer
- Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstraße 8, D-37077, Göttingen, Germany.
| | - Sonia Tarazona
- Genomics of Gene Expression Lab, Prince Felipe Research Center, Av. Eduardo Primo Yufera 3, 46012, Valencia, Spain.
| | - Christoph Sasse
- Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstraße 8, D-37077, Göttingen, Germany.
| | - Patrick Olbermann
- Research Center for Infectious Diseases, Julius-Maximilians University Würzburg, Würzburg, Germany.
| | - Jürgen Loeffler
- Laboratory WÜ4i, Medical Clinic and Policlinic II, University Clinic Würzburg, Würzburg, Germany.
| | - Sven Krappmann
- Research Center for Infectious Diseases, Julius-Maximilians University Würzburg, Würzburg, Germany. .,Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinik Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| | - Ana Conesa
- Genomics of Gene Expression Lab, Prince Felipe Research Center, Av. Eduardo Primo Yufera 3, 46012, Valencia, Spain. .,Department of Microbiology and Cell Science, Institute for Food and Agricultura Sciences, University of Florida at Gainesville, Gainesville, FL, USA.
| | - Gerhard H Braus
- Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstraße 8, D-37077, Göttingen, Germany.
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107
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Raman N, Lee MR, Lynn DM, Palecek SP. Antifungal Activity of 14-Helical β-Peptides against Planktonic Cells and Biofilms of Candida Species. Pharmaceuticals (Basel) 2015; 8:483-503. [PMID: 26287212 PMCID: PMC4588179 DOI: 10.3390/ph8030483] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 07/29/2015] [Accepted: 08/04/2015] [Indexed: 12/16/2022] Open
Abstract
Candida albicans is the most prevalent cause of fungal infections and treatment is further complicated by the formation of drug resistant biofilms, often on the surfaces of implanted medical devices. In recent years, the incidence of fungal infections by other pathogenic Candida species such as C. glabrata, C. parapsilosis and C. tropicalis has increased. Amphiphilic, helical β-peptide structural mimetics of natural antimicrobial α-peptides have been shown to exhibit specific planktonic antifungal and anti-biofilm formation activity against C. albicans in vitro. Here, we demonstrate that β-peptides are also active against clinically isolated and drug resistant strains of C. albicans and against other opportunistic Candida spp. Different Candida species were susceptible to β-peptides to varying degrees, with C. tropicalis being the most and C. glabrata being the least susceptible. β-peptide hydrophobicity directly correlated with antifungal activity against all the Candida clinical strains and species tested. While β-peptides were largely ineffective at disrupting existing Candida biofilms, hydrophobic β-peptides were able to prevent the formation of C. albicans, C. glabrata, C. parapsilosis and C. tropicalis biofilms. The broad-spectrum antifungal activity of β-peptides against planktonic cells and in preventing biofilm formation suggests the promise of this class of molecules as therapeutics.
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Affiliation(s)
- Namrata Raman
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
| | - Myung-Ryul Lee
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
| | - David M Lynn
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
- Department of Chemistry, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
| | - Sean P Palecek
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
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Trubiano JA, Chen S, Slavin MA. An Approach to a Pulmonary Infiltrate in Solid Organ Transplant Recipients. CURRENT FUNGAL INFECTION REPORTS 2015; 9:144-154. [PMID: 32218881 PMCID: PMC7091299 DOI: 10.1007/s12281-015-0229-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The onset of a pulmonary infiltrate in a solid organ transplant (SOT) recipient is both a challenging diagnostic and therapeutic challenge. We outline the potential aetiologies of a pulmonary infiltrate in a SOT recipient, with particular attention paid to fungal pathogens. A diagnostic and empirical therapy approach to a pulmonary infiltrate, especially invasive fungal disease (IFD) in SOT recipients, is provided.
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Affiliation(s)
- Jason A. Trubiano
- Infectious Diseases, Peter MacCallum Cancer Centre, East Melbourne, VIC Australia
- Infectious Diseases, Austin Health, Melbourne, VIC Australia
- Peter MacCallum Cancer Centre, 2 St Andrews Place, East Melbourne, VIC 3002 Australia
| | - Sharon Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR-Pathology West, Westmead Hospital, Sydney, Australia
| | - Monica A. Slavin
- Infectious Diseases, Peter MacCallum Cancer Centre, East Melbourne, VIC Australia
- Infectious Diseases, Royal Melbourne Hospital, Melbourne, VIC Australia
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109
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Abstract
The prevention and treatment of sepsis in the immunocompromised host present a challenging array of diagnostic and management issues. The neutropenic patient has a primary defect in innate immune responses and is susceptible to conventional and opportunistic pathogens. The solid organ transplant patient has a primary defect in adaptive immunity and is susceptible to a myriad of pathogens that require an effective cellular immune response. Risk for infections in organ transplant recipients is further complicated by mechanical, vascular, and rejection of the transplanted organ itself. The immune suppressed state can modify the cardinal signs of inflammation, making accurate and rapid diagnosis of infection and sepsis difficult. Empiric antimicrobial agents can be lifesaving in these patients, but managing therapy in an era of progressive antibiotic resistance has become a real issue. This review discusses the challenges faced when treating severe infections in these high-risk patients.
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Affiliation(s)
- Andre C Kalil
- The Transplant Infectious Disease Program, University of Nebraska Medical Center, Omaha, NE, USA
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110
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Bolton EM, Bradley JA. Avoiding immunological rejection in regenerative medicine. Regen Med 2015; 10:287-304. [DOI: 10.2217/rme.15.11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
One of the major goals of regenerative medicine is repair or replacement of diseased and damaged tissues by transfer of differentiated stem cells or stem cell-derived tissues. The possibility that these tissues will be destroyed by immunological rejection remains a challenge that can only be overcome through a better understanding of the nature and expression of potentially immunogenic molecules associated with cell replacement therapy and the mechanisms and pathways resulting in their immunologic rejection. This review draws on clinical experience of organ and tissue transplantation, and on transplantation immunology research to consider practical approaches for avoiding and overcoming the possibility of rejection of stem cell-derived tissues.
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Affiliation(s)
- Eleanor M Bolton
- Department of Surgery, University of Cambridge, Box 202, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - John Andrew Bradley
- Department of Surgery, University of Cambridge, Box 202, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
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111
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Invasive Fungal Infections in Pediatric Solid Organ Transplant Patients: Epidemiology and Management. CURRENT FUNGAL INFECTION REPORTS 2015. [DOI: 10.1007/s12281-015-0217-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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112
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Brás S, Sabino R, Laureano A, Simões H, Fernandes C, Marques-Pinto G, Cardoso J, Veríssimo C. Cutaneous infection by different Alternaria species in a liver transplant recipient. Med Mycol Case Rep 2015; 8:1-4. [PMID: 25750855 PMCID: PMC4348454 DOI: 10.1016/j.mmcr.2015.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 12/02/2022] Open
Abstract
Fungal invasive infections are rare in general population but are an emergent cause of infection in the immunocompromized population, especially in the solid organ transplant recipients. Herein the authors report a clinical case of a liver transplanted patient suffering a cutaneous co-existent infection with A. alternata as well as A. infectoria. To our knowledge this is the first case of cutaneous concomitant infection due to those two species reported not only in Portugal but also worldwide. The patient was treated with surgical excision of the lesions and oral itraconazol without relapse.
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Affiliation(s)
- Susana Brás
- Departement of Dermatology and Venereology, Curry Cabral Hospital - Centro Hospitalar de Lisboa Central, Lisbon, Portugal
| | - Raquel Sabino
- Laboratório Nacional de Referência de Infecções Parasitárias e Fúngicas, Departamento de Doenças Infecciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - André Laureano
- Departement of Dermatology and Venereology, Curry Cabral Hospital - Centro Hospitalar de Lisboa Central, Lisbon, Portugal
| | - Helena Simões
- Laboratório Nacional de Referência de Infecções Parasitárias e Fúngicas, Departamento de Doenças Infecciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
| | - Cândida Fernandes
- Departement of Dermatology and Venereology, Curry Cabral Hospital - Centro Hospitalar de Lisboa Central, Lisbon, Portugal
| | - Gabriela Marques-Pinto
- Departement of Dermatology and Venereology, Curry Cabral Hospital - Centro Hospitalar de Lisboa Central, Lisbon, Portugal
| | - Jorge Cardoso
- Departement of Dermatology and Venereology, Curry Cabral Hospital - Centro Hospitalar de Lisboa Central, Lisbon, Portugal
| | - Cristina Veríssimo
- Laboratório Nacional de Referência de Infecções Parasitárias e Fúngicas, Departamento de Doenças Infecciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
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113
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Rivera A. Protective immune responses to fungal infections. Parasite Immunol 2014; 36:453-62. [DOI: 10.1111/pim.12098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 01/10/2014] [Indexed: 02/06/2023]
Affiliation(s)
- A. Rivera
- Department of Pediatrics and Center for Immunity and Inflammation; Rutgers; Rutgers Biomedical and Health Sciences; New Jersey Medical School; Newark NJ USA
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114
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Bassiri-Jahromi S, Iravani K. Fungal brain abscess: report of three cases and review of literature. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2014. [DOI: 10.1016/s2222-1808(14)60745-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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115
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Warris A. The biology of pulmonary aspergillus infections. J Infect 2014; 69 Suppl 1:S36-41. [PMID: 25135079 DOI: 10.1016/j.jinf.2014.07.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2014] [Indexed: 01/08/2023]
Abstract
Pulmonary aspergillus infections are mainly caused by Aspergillus fumigatus and can be classified based on clinical syndromes into saphrophytic infections, allergic disease and invasive disease. Invasive pulmonary aspergillosis, occurring in immunocompromised patients, reflects the most serious disease with a high case-fatality rate. Patients with cystic fibrosis and severe asthma might develop allergic bronchopulmonary aspergillosis, while saphrophytic infections are observed in patients with lung cavities mainly due to tuberculosis. Histopathologically, a differentiation can be made into angio-invasive and airway-invasive disease. If the host response is too weak or too strong, Aspergillus species are able to cause disease characterized either by damage from the fungus itself or through an exaggerated inflammatory response of the host, in both situations leading to overt disease associated with specific clinical signs and symptoms. The unraveling of the specific host - Aspergillus interaction has not been performed to a great extent and needs attention to improve the management of those clinical syndromes.
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Affiliation(s)
- Adilia Warris
- University of Aberdeen, School of Medicine and Dentistry, Division of Applied Medicine, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
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116
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Pence MA, McElvania TeKippe E, Wallace MA, Burnham CAD. Comparison and optimization of two MALDI-TOF MS platforms for the identification of medically relevant yeast species. Eur J Clin Microbiol Infect Dis 2014; 33:1703-12. [PMID: 24800928 DOI: 10.1007/s10096-014-2115-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 04/07/2014] [Indexed: 01/14/2023]
Abstract
The rapid identification of yeast is essential for the optimization of antifungal therapy. The objective of our study was to evaluate two matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platforms, the bioMérieux VITEK MS (IVD Knowledgebase v.2.0) and Bruker Biotyper (software version 3.1), for the rapid identification of medically relevant yeast. One hundred and seventeen isolates, representing six genera and 18 species, were analyzed using multiple direct smear methods to optimize identification. Sequence analysis was the gold standard for comparison. Isolates were analyzed with VITEK MS using the direct smear method +/- a 25 % formic acid on-plate extraction. For Biotyper, isolates were analyzed using direct smear without formic acid, and with 25 % and 100 % formic acid on-plate extractions. When all methods were included, VITEK MS correctly identified 113 (96.6 %) isolates after 24 h with one misidentification, and Biotyper correctly identified 77 (65.8 %) isolates using a threshold of ≥2.0 with no misidentifications. Using a revised threshold of ≥1.7, Biotyper correctly identified 103 (88.0 %) isolates, with 3 (2.6 %) misidentifications. For both platforms, the number of identifications was significantly increased using a formic acid overlay (VITEK MS, p < 0.01; Biotyper, p < 0.001), and reducing the Biotyper threshold from ≥2.0 to ≥1.7 significantly increased the rate of identification (p < 0.001). The data in this study demonstrate that the direct smear method with on-plate formic acid extraction can be used for yeast identification on both MS platforms, and more isolates are identified using the VITEK MS system (p < 0.01).
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Affiliation(s)
- M A Pence
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, 660 S. Euclid Ave., Campus Box 8118, St. Louis, MO, 63110, USA
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Mihu MR, Pattabhi R, Nosanchuk JD. The impact of antifungals on toll-like receptors. Front Microbiol 2014; 5:99. [PMID: 24672516 PMCID: PMC3954077 DOI: 10.3389/fmicb.2014.00099] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 02/25/2014] [Indexed: 01/23/2023] Open
Abstract
Fungi are increasingly recognized as major pathogens in immunocompromised individuals. With the increase in the number of fungal infections each year and the development of resistance to current therapy, new approaches to treatment including stimulation of the immune response in addition to concurrent pharmacotherapy is ongoing. The most common invasive fungal infections are caused by Candida spp., Aspergillus spp., and Cryptococcus spp. Amphotericin B (AmB) has remained the cornerstone of therapy against many fulminant fungal infections but its use is limited by its multitude of side effects. Echinocandins are a newer class of antifungal drugs with activity against Candida spp. and Aspergillus spp. and constitutes an alternative to AmB due to superior patient tolerability and fewer side effects. Due to their oral delivery, azoles continue to be heavily used for simple and complex diseases, such as fluconazole for candidal vaginitis and voriconazole for aspergillosis. The objective of this paper is to present current knowledge regarding the multiple interactions between the broad spectrum antifungals and the innate immune response, primarily focusing on the toll-like receptors.
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Affiliation(s)
- Mircea R Mihu
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine-Montefiore Medical Center Bronx, NY, USA
| | - Rodney Pattabhi
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine-Montefiore Medical Center Bronx, NY, USA
| | - Joshua D Nosanchuk
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine-Montefiore Medical Center Bronx, NY, USA ; Department of Microbiology and Immunology, Albert Einstein College of Medicine-Montefiore Medical Center Bronx, NY, USA
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118
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Krishnan K, Ren Z, Losada L, Nierman WC, Lu LJ, Askew DS. Polysome profiling reveals broad translatome remodeling during endoplasmic reticulum (ER) stress in the pathogenic fungus Aspergillus fumigatus. BMC Genomics 2014; 15:159. [PMID: 24568630 PMCID: PMC3943501 DOI: 10.1186/1471-2164-15-159] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 02/17/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The unfolded protein response (UPR) is a network of intracellular signaling pathways that supports the ability of the secretory pathway to maintain a balance between the load of proteins entering the endoplasmic reticulum (ER) and the protein folding capacity of the ER lumen. Current evidence indicates that several pathogenic fungi rely heavily on this pathway for virulence, but there is limited understanding of the mechanisms involved. The best known functional output of the UPR is transcriptional upregulation of mRNAs involved in ER homeostasis. However, this does not take into account mechanisms of translational regulation that involve differential loading of ribosomes onto mRNAs. In this study, a global analysis of transcript-specific translational regulation was performed in the pathogenic mold Aspergillus fumigatus to determine the nature and scope of the translational response to ER stress. RESULTS ER stress was induced by treating the fungus with dithiothreitol, tunicamycin, or a thermal up-shift. The mRNAs were then fractionated on the basis of ribosome occupancy into an under-translated pool (U) and a well-translated pool (W). The mRNAs were used to interrogate microarrays and the ratio of the hybridization signal (W/U) was used as an indicator of the relative translational efficiency of a mRNA under each condition. The largest category of translationally upregulated mRNAs during ER stress encoded proteins involved in translation. Components of the ergosterol and GPI anchor biosynthetic pathways also showed increased polysome association, suggesting an important role for translational regulation in membrane and cell wall homeostasis. ER stress induced limited remodeling of the secretory pathway translatome. However, a select group of transcription factors was translationally upregulated, providing a link to subsequent modification of the transcriptome. Finally, we provide evidence that one component of the ER stress translatome is a novel mRNA isoform from the yvc1 gene that is induced by ER stress in a UPR-dependent manner. CONCLUSIONS Together, these findings define a core set of mRNAs subject to translational control during the adaptive response to acute ER stress in A. fumigatus and reveal a remarkable breadth of functions that are needed to resolve ER stress in this organism.
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Affiliation(s)
| | | | | | | | | | - David S Askew
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0529, USA.
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Patel RV, Park SW. Access to a new class of biologically active quinoline based 1,2,4-triazoles. Eur J Med Chem 2014; 71:24-30. [DOI: 10.1016/j.ejmech.2013.10.059] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/23/2013] [Accepted: 10/23/2013] [Indexed: 10/26/2022]
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120
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Zhang SX. Enhancing molecular approaches for diagnosis of fungal infections. Future Microbiol 2013; 8:1599-611. [DOI: 10.2217/fmb.13.120] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Molecular tests can improve the diagnosis of fungal infections. Despite the increasing application for fungal detection, molecular tests are still not accepted as a diagnostic criterion to define invasive fungal diseases. This limitation is largely due to a lack of a standardized method. Method standardization can be achieved by following a consensus protocol developed by a working group, by performing a molecular test in a centralized laboratory or by using a commercial assay that provides a standardized method and quality-controlled reagents. Forming a consortium or a working group consisting of large-scale diagnostic mycology laboratories can accelerate the process of validating and implementing a commercial molecular assay for clinical use through a joint effort between industry partners and clinicians. Development of molecular tests not only for the detection of fungi but also for the identification of antifungal drug resistance directly in blood, bronchoalveolar lavage fluid, cerebrospinal fluid, and formalin-fixed and paraffin-embedded tissues greatly enhances fungal diagnostic capacities. Advances of developing quantitative assays and RNA detection platforms may provide another avenue to further improve fungal diagnostics.
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Affiliation(s)
- Sean X Zhang
- Division of Medical Microbiology, Department of Pathology, Johns Hopkins University School of Medicine, Johns Hopkins Hospital, 600 Wolfe Street, Meyer B1-193, Baltimore 21287, MD, USA
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121
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Krishnan K, Askew DS. The fungal UPR: a regulatory hub for virulence traits in the mold pathogen Aspergillus fumigatus. Virulence 2013; 5:334-40. [PMID: 24189125 PMCID: PMC3956511 DOI: 10.4161/viru.26571] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic pathogen that is responsible for a life-threatening fungal infection known as invasive aspergillosis. Current therapies for the treatment of this disease continue to be associated with a poor outcome, so there is a need for more information about aspects of the fungus-host interaction that could offer novel targets for drug intervention. One attractive possibility is the unfolded protein response (UPR), an intracellular signaling network that helps the fungus meet the demand for secretion in the host environment. The major function of the UPR is to mitigate ER stress by maintaining an equilibrium between the load of client proteins entering the endoplasmic reticulum (ER) and the protein folding capacity of the organelle. However, recent findings suggest that A. fumigatus, as well as several other pathogenic fungi, also rely upon this pathway for virulence. In this review, we provide an update on the A. fumigatus UPR, discuss emerging evidence that the UPR is situated at the nexus of a number of physiological functions that are vital for the virulence of this fungus, and suggest exciting possibilities for future therapeutic targeting of this pathway for the treatment of aspergillosis.
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Affiliation(s)
- Karthik Krishnan
- Department of Pathology & Laboratory Medicine; University of Cincinnati College of Medicine; Cincinnati, OH USA
| | - David S Askew
- Department of Pathology & Laboratory Medicine; University of Cincinnati College of Medicine; Cincinnati, OH USA
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122
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Vijayvargiya P, Javed I, Moreno J, Mynt M, Kotapka M, Zaki R, Ortiz J. Pituitary aspergillosis in a kidney transplant recipient and review of the literature. Transpl Infect Dis 2013; 15:E196-200. [DOI: 10.1111/tid.12129] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/29/2013] [Accepted: 06/04/2013] [Indexed: 11/29/2022]
Affiliation(s)
- P. Vijayvargiya
- Thomas Jefferson Medical College; Thomas Jefferson University; Philadelphia Pennsylvania USA
| | - I. Javed
- Department of Surgery; Einstein Medical Center; Philadelphia Pennsylvania USA
| | - J. Moreno
- Department of Surgery; Einstein Medical Center; Philadelphia Pennsylvania USA
| | - M.A. Mynt
- Department of Pathology; Einstein Medical Center; Philadelphia Pennsylvania USA
| | - M. Kotapka
- Department of Surgery; Einstein Medical Center; Philadelphia Pennsylvania USA
| | - R. Zaki
- Department of Surgery; Einstein Medical Center; Philadelphia Pennsylvania USA
| | - J. Ortiz
- Department of Surgery; Einstein Medical Center; Philadelphia Pennsylvania USA
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Multicenter study evaluating the Vitek MS system for identification of medically important yeasts. J Clin Microbiol 2013; 51:2267-72. [PMID: 23658267 DOI: 10.1128/jcm.00680-13] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The optimal management of fungal infections is correlated with timely organism identification. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is revolutionizing the identification of yeasts isolated from clinical specimens. We present a multicenter study assessing the performance of the Vitek MS system (bioMérieux) in identifying medically important yeasts. A collection of 852 isolates was tested, including 20 Candida species (626 isolates, including 58 C. albicans, 62 C. glabrata, and 53 C. krusei isolates), 35 Cryptococcus neoformans isolates, and 191 other clinically relevant yeast isolates; in total, 31 different species were evaluated. Isolates were directly applied to a target plate, followed by a formic acid overlay. Mass spectra were acquired using the Vitek MS system and were analyzed using the Vitek MS v2.0 database. The gold standard for identification was sequence analysis of the D2 region of the 26S rRNA gene. In total, 823 isolates (96.6%) were identified to the genus level and 819 isolates (96.1%) were identified to the species level. Twenty-four isolates (2.8%) were not identified, and five isolates (0.6%) were misidentified. Misidentified isolates included one isolate of C. albicans (n = 58) identified as Candida dubliniensis, one isolate of Candida parapsilosis (n = 73) identified as Candida pelliculosa, and three isolates of Geotrichum klebahnii (n = 6) identified as Geotrichum candidum. The identification of clinically relevant yeasts using MS is superior to the phenotypic identification systems currently employed in clinical microbiology laboratories.
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Effects of a defective endoplasmic reticulum-associated degradation pathway on the stress response, virulence, and antifungal drug susceptibility of the mold pathogen Aspergillus fumigatus. EUKARYOTIC CELL 2013; 12:512-9. [PMID: 23355008 DOI: 10.1128/ec.00319-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Proteins that are destined for release outside the eukaryotic cell, insertion into the plasma membrane, or delivery to intracellular organelles are processed and folded in the endoplasmic reticulum (ER). An imbalance between the level of nascent proteins entering the ER and the organelle's ability to manage that load results in the accumulation of unfolded proteins. Terminally unfolded proteins are disposed of by ER-associated degradation (ERAD), a pathway that transports the aberrant proteins across the ER membrane into the cytosol for proteasomal degradation. The ERAD pathway was targeted in the mold pathogen Aspergillus fumigatus by deleting the hrdA gene, encoding the A. fumigatus ortholog of Hrd1, the E3 ubiquitin ligase previously shown to contribute to ERAD in other species. Loss of HrdA was associated with impaired degradation of a folding-defective ERAD substrate, CPY*, as well as activation of the unfolded-protein response (UPR). The ΔhrdA mutant showed resistance to voriconazole and reduced thermotolerance but was otherwise unaffected by a variety of environmental stressors. A double-deletion mutant deficient in both HrdA and another component of the same ERAD complex, DerA, was defective in secretion and showed hypersensitivity to ER, thermal, and cell wall stress. However, the ΔhrdA ΔderA mutant remained virulent in mouse and insect infection models. These data demonstrate that HrdA and DerA support complementary ERAD functions that promote survival under conditions of ER stress but are dispensable for virulence in the host environment.
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