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Shankar J, Cerqueira GC, Wortman JR, Clemons KV, Stevens DA. RNA-Seq Profile Reveals Th-1 and Th-17-Type of Immune Responses in Mice Infected Systemically with Aspergillus fumigatus. Mycopathologia 2018; 183:645-658. [PMID: 29500637 PMCID: PMC6067991 DOI: 10.1007/s11046-018-0254-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/19/2018] [Indexed: 01/15/2023]
Abstract
With the increasing numbers of immunocompromised hosts, Aspergillus fumigatus emerges as a lethal opportunistic fungal pathogen. Understanding innate and acquired immunity responses of the host is important for a better therapeutic strategy to deal with aspergillosis patients. To determine the transcriptome in the kidneys in aspergillosis, we employed RNA-Seq to obtain single 76-base reads of whole-genome transcripts of murine kidneys on a temporal basis (days 0; uninfected, 1, 2, 3 and 8) during invasive aspergillosis. A total of 6284 transcripts were downregulated, and 5602 were upregulated compared to baseline expression. Gene ontology enrichment analysis identified genes involved in innate and adaptive immune response, as well as iron binding and homeostasis, among others. Our results showed activation of pathogen recognition receptors, e.g., β-defensins, C-type lectins (e.g., dectin-1), Toll-like receptors (TLR-2, TLR-3, TLR-8, TLR-9 and TLR-13), as well as Ptx-3 and C-reactive protein among the soluble receptors. Upregulated transcripts encoding various differentiating cytokines and effector proinflammatory cytokines, as well as those encoding for chemokines and chemokine receptors, revealed Th-1 and Th-17-type immune responses. These studies form a basic dataset for experimental prioritization, including other target organs, to determine the global response of the host against Aspergillus infection.
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Affiliation(s)
- Jata Shankar
- Jaypee University of Information Technology, Solan, HP, India
- California Institute for Medical Research, San Jose, CA, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | | | | | - Karl V Clemons
- California Institute for Medical Research, San Jose, CA, USA.
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA.
| | - David A Stevens
- California Institute for Medical Research, San Jose, CA, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
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2
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Desoubeaux G, Cray C. Rodent Models of Invasive Aspergillosis due to Aspergillus fumigatus: Still a Long Path toward Standardization. Front Microbiol 2017; 8:841. [PMID: 28559881 PMCID: PMC5432554 DOI: 10.3389/fmicb.2017.00841] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/24/2017] [Indexed: 01/09/2023] Open
Abstract
Invasive aspergillosis has been studied in laboratory by the means of plethora of distinct animal models. They were developed to address pathophysiology, therapy, diagnosis, or miscellaneous other concerns associated. However, there are great discrepancies regarding all the experimental variables of animal models, and a thorough focus on them is needed. This systematic review completed a comprehensive bibliographic analysis specifically-based on the technical features of rodent models infected with Aspergillus fumigatus. Out the 800 articles reviewed, it was shown that mice remained the preferred model (85.8% of the referenced reports), above rats (10.8%), and guinea pigs (3.8%). Three quarters of the models involved immunocompromised status, mainly by steroids (44.4%) and/or alkylating drugs (42.9%), but only 27.7% were reported to receive antibiotic prophylaxis to prevent from bacterial infection. Injection of spores (30.0%) and inhalation/deposition into respiratory airways (66.9%) were the most used routes for experimental inoculation. Overall, more than 230 distinct A. fumigatus strains were used in models. Of all the published studies, 18.4% did not mention usage of any diagnostic tool, like histopathology or mycological culture, to control correct implementation of the disease and to measure outcome. In light of these findings, a consensus discussion should be engaged to establish a minimum standardization, although this may not be consistently suitable for addressing all the specific aspects of invasive aspergillosis.
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Affiliation(s)
- Guillaume Desoubeaux
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA.,Service de Parasitologie-Mycologie-Médecine tropicale, Centre Hospitalier Universitaire de ToursTours, France.,Centre d'Etude des Pathologies Respiratoires (CEPR) Institut National de la Santé et de la Recherche Médicale U1100/Équipe 3, Université François-RabelaisTours, France
| | - Carolyn Cray
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA
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3
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Greppi MC, Guillot J, Melloul E, Bourdoiseau G, Lepage O, Cadoré JL. Experimental induction of mycotic plaques in the guttural pouches of horses. Med Mycol 2017; 55:308-313. [PMID: 27703018 DOI: 10.1093/mmy/myw073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 08/01/2016] [Indexed: 11/14/2022] Open
Abstract
Guttural pouch mycosis (GPM) is a rare but potentially life-threatening condition in horses. GPM is caused by a fungal invasion into the mucosal lining of the guttural pouches and, frequently, the associated neurovascular structures. Although several species of fungi have been associated with this disease, Aspergillus spp. appear to be the most common isolated from the guttural pouches. However, it remains unclear which are the predisposing factors leading to the development of the infection. The objectives of the present study were to experimentally reproduce an infection by Aspergillus fumigatus and to follow the natural evolution of the mycosis. Eight guttural pouches from four horses were experimentally infected by endoscopy-guided intrapouch inoculation of A. fumigatus culture. Horses were monitored for clinical signs and development of fungal plaques through endoscopic examination. Mycotic lesions were observed in all the horses and a spontaneous regression was observed within 15-28 days. No development of clinical signs was noticed. In conclusion, we were able to induce the development of mycotic lesions and to observe a natural regression of these lesions without clinical signs.
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Affiliation(s)
- Maria Carla Greppi
- Université de Lyon, Vetagro-sup, Campus Vétérinaire de Lyon, Equine Department, Marcy l'Etoile, France
| | - Jacques Guillot
- UPE, Ecole nationale vétérinaire d'Alfort, EA 7380 Dynamyc, EnvA, UPEC, Maisons-Alfort, France
| | - Elise Melloul
- UPE, Ecole nationale vétérinaire d'Alfort, EA 7380 Dynamyc, EnvA, UPEC, Maisons-Alfort, France
| | - Gilles Bourdoiseau
- Université de Lyon, Vetagro-sup, Campus Vétérinaire de Lyon, Parasitology, Marcy l'Etoile, France
| | - Olivier Lepage
- Université de Lyon, Vetagro-sup, Campus Vétérinaire de Lyon, Equine Department, Marcy l'Etoile, France
| | - Jean-Luc Cadoré
- Université de Lyon, Vetagro-sup, Campus Vétérinaire de Lyon, Equine Department, Marcy l'Etoile, France.,UMR754 INRA Université Lyon 1, "Rétrovirus et Pathologie Comparée," Equipe "Rétrovirus, évolution et cancer," Université Lyon 1, Lyon, France
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4
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Ong V, Hough G, Schlosser M, Bartizal K, Balkovec JM, James KD, Krishnan BR. Preclinical Evaluation of the Stability, Safety, and Efficacy of CD101, a Novel Echinocandin. Antimicrob Agents Chemother 2016; 60:6872-6879. [PMID: 27620474 PMCID: PMC5075098 DOI: 10.1128/aac.00701-16] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 08/04/2016] [Indexed: 12/20/2022] Open
Abstract
Fungal infections pose a significant public health burden with high morbidity and mortality. CD101 is a novel echinocandin under development for the treatment and prevention of systemic Candida infections. Preclinical studies were conducted to evaluate the metabolic stability, plasma protein binding, pharmacokinetics, toxicity, and efficacy of CD101 at various dose levels. CD101 was stable to biotransformation in rat, monkey, and human liver microsomes and rat, monkey, dog, and human hepatocytes. In vitro studies suggest minimal interaction with recombinant cytochrome P450 enzymes (50% inhibitory concentrations [IC50s] of >10 μM). Similar to anidulafungin, CD101 bound avidly (>98%) to human, mouse, rat, and primate plasma proteins. In a 2-week repeat-dose comparison study, CD101 was well tolerated in rats (no effects on body weight, hematology, coagulation, or urinalysis). In contrast, administration of anidulafungin (at comparable exposure levels) resulted in reduced body weight, decreases in red blood cell, hemoglobin, hematocrit, mean cell volume, mean corpuscular hemoglobin, platelet, and reticulocyte counts, increases in neutrophil and eosinophil counts, polychromasia, and decreased activated partial thromboplastin time. Elevated plasma transaminases, total bilirubin, cholesterol, and globulin, dark and enlarged spleens, and single-cell hepatocyte necrosis were also observed for anidulafungin but not CD101. Hepatotoxicity may be due to the inherent chemical lability of anidulafungin generating potentially reactive intermediates. A glutathione trapping experiment confirmed the formation of a reactive species from anidulafungin, whereas CD101 did not exhibit instability or reactive intermediates. CD101 showed antifungal activity against Candida and Aspergillus infections in neutropenic mice. These preclinical studies demonstrated that CD101 is chemically and metabolically stable, well tolerated with no hepatotoxicity, and efficacious as an antifungal agent.
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Affiliation(s)
- Voon Ong
- Cidara Therapeutics, Inc., San Diego, California, USA
| | - Grayson Hough
- Cidara Therapeutics, Inc., San Diego, California, USA
| | | | - Ken Bartizal
- Cidara Therapeutics, Inc., San Diego, California, USA
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5
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Animal models of invasive aspergillosis for drug discovery. Drug Discov Today 2014; 19:1380-6. [DOI: 10.1016/j.drudis.2014.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 04/10/2014] [Accepted: 06/09/2014] [Indexed: 02/03/2023]
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6
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El-Muzghi AAM, Mirkov I, Djokic J, Popov Aleksandrov A, Miljkovic D, Glamoclija J, Kataranovski D, Kataranovski M. Regional cytokine responses to pulmonary aspergillosis in immunocompetent rats. Immunobiology 2013; 218:1514-23. [DOI: 10.1016/j.imbio.2013.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 05/21/2013] [Accepted: 05/22/2013] [Indexed: 10/26/2022]
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7
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Mavridou E, Meletiadis J, Jancura P, Abbas S, Arendrup MC, Melchers WJG, Heskes T, Mouton JW, Verweij PE. Composite survival index to compare virulence changes in azole-resistant Aspergillus fumigatus clinical isolates. PLoS One 2013; 8:e72280. [PMID: 23991080 PMCID: PMC3753310 DOI: 10.1371/journal.pone.0072280] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 07/15/2013] [Indexed: 11/18/2022] Open
Abstract
Understanding resistance to antifungal agents in Aspergillus fumigatus is of increasing importance for the treatment of invasive infections in immunocompromised patients. Although a number of molecular resistance mechanisms are described in detail, the potential accompanying virulence changes and impact on clinical outcome have had little attention. We developed a new measure of survival, the composite survival index (CSI) to use as a measure of the virulence properties of A. fumigatus. Using a novel mathematical model we found a strong correlation between the in vitro growth characteristics and virulence in vivo expressed as CSI. Our model elucidates how three critical parameters (the lag phase (τ), decay constant (λ), and growth rate (ν)) interact with each other resulting in a CSI that correlated with virulence. Hence, strains with a long lag phase and high decay constant were less virulent in a murine model of invasive aspergillosis, whereas high virulence for isolates with a high CSI was associated in vitro with rapid growth and short lag phases. Resistant isolates with cyp51A mutations, which account for the majority of azole resistant aspergillosis cases, did not show a lower virulence compared to azole-susceptible isolates. In contrast, the CSI index revealed that a non-cyp51A-mediated resistance mechanism was associated with a dramatic decrease in CSI. Because of its predictive value, the mathematical model developed may serve to explore strain characteristics in vitro to predict virulence in vivo and significantly reduce the number of experimental animals required in such studies. The proposed measure of survival, the CSI can be used more in a general form in survival studies to explore optimal treatment options.
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Affiliation(s)
- Eleftheria Mavridou
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- * E-mail: (EM); (PEV)
| | - Joseph Meletiadis
- Laboratory for Clinical Microbiology, Attikon University General Hospital, Athens, Greece
| | - Pavol Jancura
- Institute for Computing and Information Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Saiden Abbas
- Institute for Computing and Information Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Maiken C. Arendrup
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
| | - Tom Heskes
- Institute for Computing and Information Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Johan W. Mouton
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands
- * E-mail: (EM); (PEV)
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8
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Experimental evidence that granulocyte transfusions are efficacious in treatment of neutropenic hosts with pulmonary aspergillosis. Antimicrob Agents Chemother 2013; 57:1882-7. [PMID: 23380731 DOI: 10.1128/aac.02533-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although polymorphonuclear leukocytes (PMNs) are powerfully anti-Aspergillus, transfusion therapy remains controversial, with conflicting results, and experimental support has been lacking. We devised a pulmonary infection model in neutropenic BALB/c mice, used an antibacterial regimen to prevent confounding sepsis, and optimized PMN induction, purifications, and dose. Mice were given 150 mg/kg cyclophosphamide every 4 days and a gentamicin-vancomycin-clindamycin-imipenem regimen daily beginning 4 days before intranasal challenge with 5 × 10(5) Aspergillus conidia. This regimen produced leukopenia (~10% of normal white blood cell [WBC] count; ≤ 10% PMNs) for 10 days, without bacterial superinfection. PMN donors given 100 μg/kg recombinant murine granulocyte colony-stimulating factor (G-CSF) for 10 days yielded 11 × 10(7) to 13.6 × 10(7) WBC/ml (81 to 87% PMNs). Infected mice were given PMN transfusions intravenously. In 2 experiments with up to 70% mortality of neutropenic controls, transfusion of 10(7) PMNs 1 and 4 days after challenge had negligible effects on peripheral WBC counts but improved survival (P = 0.007, 0.02), decreased lung CFU (P = 0.03, 0.005), and cleared infection in 28 to 50% of survivors. Transfusion of 5 × 10(6) PMNs showed partial protection. Transfusions given every other day did not improve protection. Our present results provide an experimental basis for enthusiasm for PMN transfusions in the therapy of aspergillosis in humans.
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9
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Leleu C, Menotti J, Meneceur P, Choukri F, Sulahian A, Garin YJF, Derouin F. Efficacy of liposomal amphotericin B for prophylaxis of acute or reactivation models of invasive pulmonary aspergillosis. Mycoses 2012; 56:241-9. [DOI: 10.1111/myc.12011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Mirkov I, Stosic-Grujicic S, Kataranovski M. Host immune defense against Aspergillus fumigatus: insight from experimental systemic (disseminated) infection. Immunol Res 2012; 52:120-6. [PMID: 22388638 DOI: 10.1007/s12026-012-8274-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Model of systemic Aspergillus fumigatus infection induced by intravenous application of conidia is suitable for studying important aspects of invasive aspergillosis including relationship between infection and mortality, dissemination of infection and immune mechanisms involved in host resistance to this fungus. Use of this model allows the investigation of both innate and adaptive immune response characteristics in resistant/susceptible host, and investigating the contribution of genetic background and cytokine gene deficiency improves the knowledge of the diversity of mechanisms of immune response to Aspergillus infection. Studying of various aspects of systemic aspergillosis contributes to development of antifungal drugs.
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Affiliation(s)
- I Mirkov
- Department of Ecology, Institute for Biological Research Sinisa Stankovic, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia
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11
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Kalkanci A, Kadioglu A, Wilson D, Jacobsen MD. Gene expression in fungi. IMA Fungus 2012; 2:29-32. [PMID: 22679585 PMCID: PMC3317368 DOI: 10.5598/imafungus.2011.02.01.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Accepted: 05/06/2011] [Indexed: 10/24/2022] Open
Abstract
This contribution is based on the four presentations made at the Special Interest Group (SIG) meeting titled Gene Expression in Fungi held during IMC9 in Edinburgh. This overview is independent from other articles published or that will be published by each speaker. In the SIG meeting, basic principles of in vivo animal models for virulence studies were discussed. Infection associated genes of Candida albicans and fungal adaptation to the host was summarized. Azole susceptibility was evaluated as a combined result of several changes in expression of pertinent genes. Gene transfer in fungi, resulting in fungal evolution and gene adaptation to environmental factors, was reported.
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Affiliation(s)
- Ayse Kalkanci
- Gazi University Faculty of Medicine, Department of Medical Microbiology, Ankara, 06500 Turkey
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12
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Clemons KV, Schwartz JA, Stevens DA. Therapeutic and toxicologic studies in a murine model of invasive pulmonary aspergillosis. Med Mycol 2011; 49:834-47. [PMID: 21539507 DOI: 10.3109/13693786.2011.577822] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Invasive pulmonary aspergillosis remains problematic in immunocompromised patient populations. We studied potential therapeutic options in a murine model of pulmonary aspergillosis in triamcinolone-suppressed DBA/2 mice infected intranasally with conidia from Aspergillus fumigatus. Mice were treated with liposomal-amphotericin B (AmBi; AmBisome), lipid-complexed amphotericin B (ABLC; Abelcet), voriconazole (VCZ), micafungin (MICA), caspofungin (CAS) or deoxycholate amphotericin B (AMBd) given alone or in combination. Monotherapy with AmBi, ABLC, AMBd, CAS or MICA had activity in prolonging survival; however, only AMBd or CAS reduced fungal burden in the lungs and kidneys. Combinations of AmBi plus CAS or MICA prolonged survival, but were not better than monotherapy. VCZ was ineffective and AMBd plus CAS showed a possible antagonism. AmBi or ABLC at higher dosages, or loading-doses of AmBi resulted in reduced survival. Histopathology showed increased incidence of serious renal and mild hepatic toxicity in triamcinolone-treated mice given an amphotericin B regimen compared to no or only triamcinolone (minimal renal changes occurred with CAS or VCZ with or without triamcinolone); suggestive of combined toxicity of triamcinolone and the amphotericin B in AmBi or ABLC. Infected treated mice showed progressive pulmonary disease including abscesses, angioinvasion and abundant intralesional fungi. High loading-doses of AmBi were associated with nephrosis and damage to other tissues. No monotherapy or combination regimen showed superiority for the treatment of pulmonary aspergillosis in corticosteroid suppressed mice and the potential for combined drug toxicity was enhanced in these mice. High dosages of lipid-formulated amphotericin B also proved unsatisfactory. Additional studies are needed to evaluate improved treatment.
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Affiliation(s)
- Karl V Clemons
- California Institute for Medical Research, San Jose, California, USA.
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13
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Guarro J. Lessons from animal studies for the treatment of invasive human infections due to uncommon fungi. J Antimicrob Chemother 2011; 66:1447-66. [PMID: 21493649 DOI: 10.1093/jac/dkr143] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Clinical experience in the management of opportunistic infections, especially those caused by less common fungi, is, due to their rarity, very scarce; therefore, the most effective treatments remain unknown. The ever-increasing numbers of fungal infections due to opportunistic fungi have repeatedly proven the limitations of the antifungal armamentarium. Moreover, some of these fungi, such as Fusarium spp. or Scedosporium spp., are innately resistant to almost all the available antifungal drugs, which makes the development of new and effective therapies a high priority. Since it is difficult to conduct randomized clinical trials in these uncommon mycoses, the use of animal models is a good alternative for evaluating new therapies. This is an extensive review of the numerous studies that have used animal models for this purpose against a significant number of less common fungi. A table describing the different studies performed on the efficacy of the different drugs tested is included for each fungal species. In addition, there is a summary table showing the conclusions that can be derived from the analysis of the studies and listing the drugs that showed the best results. Considering the wide variability in the response to the antifungals that the different strains of a given species can show, the table highlights the drugs that showed positive results using at least two parameters for evaluating efficacy against at least two different strains without showing any negative results. These data can be very useful for guiding the treatment of rare infections when there is very little experience or when controversial results exist, or when treatment fails.
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Affiliation(s)
- Josep Guarro
- Mycology Unit, Medical School, IISPV, Rovira i Virgili University, 43201 Reus, Spain.
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14
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Morton CO, Clemons KV, Springer J, Mueller JG, Rogers TR, Stevens DA, Kurzai O, Einsele H, Loeffler J. Real-time PCR and quantitative culture for monitoring of experimental Aspergillus fumigatus intracranial infection in neutropenic mice. J Med Microbiol 2011; 60:913-919. [PMID: 21436369 DOI: 10.1099/jmm.0.028399-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The central nervous system (CNS) is the most common site of dissemination during Aspergillus infection. PCR has the potential to facilitate early diagnosis of CNS aspergillosis, which could assist in reducing disease mortality. In two experiments, neutropenic CD-1 male mice were infected intracranially with 5×10⁶ conidia of Aspergillus fumigatus. At time points up to 120 h after infection, mice were euthanized and samples of blood, brain, spinal cord and cerebrospinal fluid (CSF) were taken. The brain fungal burden was determined by quantitative culture, and fungal DNA was detected by quantitative PCR. Plating for A. fumigatus from the brain confirmed that all mice had burdens of log₁₀>3 from 4 to 120 h after infection. A. fumigatus DNA was detected in blood (88 %), brain (96 %), CSF (52 %) and spinal cord (92 %) samples. The brain and spinal cord contained the highest concentrations of fungal DNA. Adapting the extraction protocol to maximize yield from small sample volumes (10 µl CSF or 200 µl blood) allowed PCR detection of A. fumigatus in infected mice, suggesting the use of CSF and blood as diagnostic clinical samples for CNS aspergillosis.
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Affiliation(s)
- C Oliver Morton
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College Dublin, Dublin 8, Ireland
| | - Karl V Clemons
- California Institute for Medical Research, San Jose, CA 95128, USA.,Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA 94305, USA.,Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, CA 95128-2699, USA
| | - Jan Springer
- Universität Wuerzburg, Medizinische Klinik & Poliklinik II, Wuerzburg, Germany
| | - Justus G Mueller
- Pathologisches Institut der Universität Wuerzburg, Wuerzburg, Germany
| | - Thomas R Rogers
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College Dublin, Dublin 8, Ireland
| | - David A Stevens
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA 94305, USA.,Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, CA 95128-2699, USA.,California Institute for Medical Research, San Jose, CA 95128, USA
| | - Oliver Kurzai
- Friedrich-Schiller-Universität Jena, Septomics Research Centre, Leibniz Institute for Natural Products Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Hermann Einsele
- Universität Wuerzburg, Medizinische Klinik & Poliklinik II, Wuerzburg, Germany
| | - Juergen Loeffler
- Universität Wuerzburg, Medizinische Klinik & Poliklinik II, Wuerzburg, Germany
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15
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Capilla J, Clemons KV, Stevens DA. Animal models: an important tool in mycology. Med Mycol 2007; 45:657-84. [PMID: 18027253 PMCID: PMC7107685 DOI: 10.1080/13693780701644140] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 08/22/2007] [Indexed: 10/29/2022] Open
Abstract
Animal models of fungal infections are, and will remain, a key tool in the advancement of the medical mycology. Many different types of animal models of fungal infection have been developed, with murine models the most frequently used, for studies of pathogenesis, virulence, immunology, diagnosis, and therapy. The ability to control numerous variables in performing the model allows us to mimic human disease states and quantitatively monitor the course of the disease. However, no single model can answer all questions and different animal species or different routes of infection can show somewhat different results. Thus, the choice of which animal model to use must be made carefully, addressing issues of the type of human disease to mimic, the parameters to follow and collection of the appropriate data to answer those questions being asked. This review addresses a variety of uses for animal models in medical mycology. It focuses on the most clinically important diseases affecting humans and cites various examples of the different types of studies that have been performed. Overall, animal models of fungal infection will continue to be valuable tools in addressing questions concerning fungal infections and contribute to our deeper understanding of how these infections occur, progress and can be controlled and eliminated.
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Affiliation(s)
- Javier Capilla
- California Institute for Medical Research, San Jose, USA
- Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, USA
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Karl V. Clemons
- California Institute for Medical Research, San Jose, USA
- Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, USA
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - David A. Stevens
- California Institute for Medical Research, San Jose, USA
- Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, USA
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
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Zimmerli S, Knecht U, Leib SL. A model of cerebral aspergillosis in non-immunosuppressed nursing rats. Acta Neuropathol 2007; 114:411-8. [PMID: 17602232 DOI: 10.1007/s00401-007-0255-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/04/2007] [Accepted: 06/08/2007] [Indexed: 10/23/2022]
Abstract
Central nervous system aspergillosis is an often fatal complication of invasive Aspergillus infection. Relevant disease models are needed to study the pathophysiology of cerebral aspergillosis and to develop novel therapeutic approaches. This study presents a model of central nervous system aspergillosis that mimics important aspects of human disease. Eleven-day-old non-immunosuppressed male Wistar rats were infected by an intracisternal injection of 10 mul of a conidial suspension of Aspergillus fumigatus. An inoculum of 7.18 log(10) colony-forming units (CFU) consistently produced cerebral infection and resulted in death of all animals (n = 25) within 3-10 days. Median survival time was 3 days. Histomorphologically, all animals developed intracerebral abscesses (2-26 per brain) containing abundant fungal hyphae and neutrophils. Fungal culture of cortical homogenates yielded maximal growth on day 3 after infection (5.4 log(10) CFU/g, n = 15) that declined over time. Galactomannan concentrations in cortical homogenates, assessed as an index for hyphal burden, peaked on days 3-5. Fungal infection spread to peripheral organs in 83% of animals. Fungal burden in lung, liver, spleen and kidney was two orders of magnitude lower than in the brain. The successful establishment of a model of cerebral aspergillosis in a non-immunosuppressed host provides the opportunity to investigate mechanisms of disease and to develop novel treatment regimens for this commonly fatal infection.
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Affiliation(s)
- Stefan Zimmerli
- Institute for Infectious Diseases, University of Bern, Friedbuehlstr, 51, PO Box 61, 3010, Bern, Switzerland.
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Thevissen K, Kristensen HH, Thomma BPHJ, Cammue BPA, François IEJA. Therapeutic potential of antifungal plant and insect defensins. Drug Discov Today 2007; 12:966-71. [PMID: 17993416 DOI: 10.1016/j.drudis.2007.07.016] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 07/17/2007] [Accepted: 07/18/2007] [Indexed: 12/12/2022]
Abstract
To defend themselves against invading fungal pathogens, plants and insects largely depend on the production of a wide array of antifungal molecules, including antimicrobial peptides such as defensins. Interestingly, plant and insect defensins display antimicrobial activity not only against plant and insect pathogens but also against human fungal pathogens, including Candida spp. and Aspergillus spp. This review focuses on these defensins as novel leads for antifungal therapeutics. Their mode of action, involving interaction with fungus-specific sphingolipids, and heterologous expression, required for cost-effective production, are major assets for development of plant and insect defensins as antifungal leads. Studies evaluating their in vivo antifungal efficacy demonstrate their therapeutic potential.
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Affiliation(s)
- Karin Thevissen
- Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
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Abstract
Experimental models of coccidioidomycosis performed using various laboratory animals have been, and remain, a critical component of elucidation and understanding of the pathogenesis and host resistance to infection with Coccidioides spp., as well as to development of more efficacious antifungal therapies. The general availability of genetically defined strains, immunological reagents, ease of handling, and costs all contribute to the use of mice as the primary laboratory animal species for models of this disease. Five types of murine models are studied and include primary pulmonary disease, intraperitoneal with dissemination, intravenous infection emulating systemic disease, and intracranial or intrathecal infection emulating meningeal disease. Each of these models has been used to examine various aspects of host resistance, pathogenesis, or antifungal therapy. Other rodent species, such as rat, have been used much less frequently. A rabbit model of meningeal disease, established by intracisternal infection, has proven to model human meningitis well. This model is useful in studies of host response, as well as in therapy studies. A variety of other animal species including dogs, primates, and guinea pigs have been used to study host response and vaccine efficacy. However, cost and increased needs of animal care and husbandry are limitations that influence the use of the larger animal species.
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Affiliation(s)
- Karl V Clemons
- Division of Infectious Diseases, Santa Clara Valley Medical Center, 751 South Bascom Ave., San Jose, CA 95128-2699, USA.
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