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Vanhoffelen E, Vermoesen L, Michiels L, Lagrou K, Reséndiz-Sharpe A, Vande Velde G. Sensitive bioluminescence imaging of cryptococcosis in Galleria mellonella improves antifungal screening under in vivo conditions. Virulence 2024; 15:2327883. [PMID: 38465639 PMCID: PMC10939141 DOI: 10.1080/21505594.2024.2327883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/28/2024] [Indexed: 03/12/2024] Open
Abstract
Cryptococcus neoformans is an environmental yeast that primarily affects immunocompromised individuals, causing respiratory infections and life-threatening meningoencephalitis. Treatment is complicated by limited antifungal options, with concerns such as adverse effects, dose-limiting toxicity, blood-brain barrier permeability, and resistance development, emphasizing the critical need to optimize and expand current treatment options against invasive cryptococcosis. Galleria mellonella larvae have been introduced as an ethical intermediate for in vivo testing, bridging the gap between in vitro antifungal screening and mouse studies. However, current infection readouts in G. mellonella are indirect, insensitive, or invasive, which hampers the full potential of the model. To address the absence of a reliable non-invasive method for tracking infection, we longitudinally quantified the cryptococcal burden in G. mellonella using bioluminescence imaging (BLI). After infection with firefly luciferase-expressing C. neoformans, the resulting bioluminescence signal was quantitatively validated using colony-forming unit analysis. Longitudinal comparison of BLI to health and survival analysis revealed increased sensitivity of BLI in discriminating cryptococcal burden during early infection. Furthermore, BLI improved the detection of treatment efficacy using first-line antifungals, thereby benchmarking this model for antifungal testing. In conclusion, we introduced BLI as a real-time, quantitative readout of cryptococcal burden in G. mellonella over time, enabling more sensitive and reliable antifungal screening.
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Affiliation(s)
- Eliane Vanhoffelen
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
| | - Lori Vermoesen
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
| | - Lauren Michiels
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Microbiology, KULeuven, Leuven, Belgium
- Department of Laboratory Medicine, National Reference Center for Mycosis, University Hospitals Leuven, Leuven, Belgium
| | | | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
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Curtis A, Dobes P, Marciniak J, Hurychova J, Hyrsl P, Kavanagh K. Characterization of Aspergillus fumigatus secretome during sublethal infection of Galleria mellonella larvae. J Med Microbiol 2024; 73. [PMID: 38836745 DOI: 10.1099/jmm.0.001844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024] Open
Abstract
Introduction. The fungal pathogen Aspergillus fumigatus can induce prolonged colonization of the lungs of susceptible patients, resulting in conditions such as allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis.Hypothesis. Analysis of the A. fumigatus secretome released during sub-lethal infection of G. mellonella larvae may give an insight into products released during prolonged human colonisation.Methodology. Galleria mellonella larvae were infected with A. fumigatus, and the metabolism of host carbohydrate and proteins and production of fungal virulence factors were analysed. Label-free qualitative proteomic analysis was performed to identify fungal proteins in larvae at 96 hours post-infection and also to identify changes in the Galleria proteome as a result of infection.Results. Infected larvae demonstrated increasing concentrations of gliotoxin and siderophore and displayed reduced amounts of haemolymph carbohydrate and protein. Fungal proteins (399) were detected by qualitative proteomic analysis in cell-free haemolymph at 96 hours and could be categorized into seven groups, including virulence (n = 25), stress response (n = 34), DNA repair and replication (n = 39), translation (n = 22), metabolism (n = 42), released intracellular (n = 28) and cellular development and cell cycle (n = 53). Analysis of the Gallerial proteome at 96 hours post-infection revealed changes in the abundance of proteins associated with immune function, metabolism, cellular structure, insect development, transcription/translation and detoxification.Conclusion. Characterizing the impact of the fungal secretome on the host may provide an insight into how A. fumigatus damages tissue and suppresses the immune response during long-term pulmonary colonization.
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Affiliation(s)
- Aaron Curtis
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Pavel Dobes
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jacek Marciniak
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jana Hurychova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Hyrsl
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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3
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Genç TT, Kaya S, Günay M, Çakaloğlu Ç. Humoral immune response of Galleria mellonella after mono- and co-injection with Hypericum perforatum extract and Candida albicans. APMIS 2024; 132:358-370. [PMID: 38344892 DOI: 10.1111/apm.13383] [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: 06/08/2023] [Accepted: 01/24/2024] [Indexed: 04/16/2024]
Abstract
Galleria mellonella is used as a model organism to study the innate immune response of insects. In this study, the humoral immune response was assessed by examining phenoloxidase activity, fungal burden, and the expression of phenoloxidase and antimicrobial peptide genes at different time point following separate and combined injections of Hypericum perforatum extract and a nonlethal dose of Candida albicans. The administration of a plant extract at low doses increased phenoloxidase activity, while higher doses had no effect. Similarly, co-injection of a low dose of the extract with the pathogen allowed half of the yeast cells to survive after 24 h. Co-injection of plant extract with the pathogen decreased the phenoloxidase activity at the end of 4 h compared to C. albicans mono-injection. The phenoloxidase gene expressions was reduced in all experimental conditions with respect to the control. When plant extracts and the pathogen were administered together, gallerimycin and hemolin gene expressions were considerably higher compared to mono-injections of plant extracts and the pathogen. The results of this study reveal that gene activation and regulatory mechanisms may change for each immune gene, and that recognition and signaling pathways may differ depending on the involved immunoregulator.
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Affiliation(s)
- Tülay Turgut Genç
- Department of Biology, Science Faculty, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Serhat Kaya
- Department of Biology, Science Faculty, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Melih Günay
- Graduate School of Natural and Applied Sciences, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Çağla Çakaloğlu
- Graduate School of Natural and Applied Sciences, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
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de Andrade VM, de Oliveira VDM, Barcick U, Ramu VG, Heras M, Bardají ER, Castanho MARB, Zelanis A, Capella A, Junqueira JC, Conceição K. Mechanistic insights on the antibacterial action of the kyotorphin peptide derivatives revealed by in vitro studies and Galleria mellonella proteomic analysis. Microb Pathog 2024; 189:106607. [PMID: 38437995 DOI: 10.1016/j.micpath.2024.106607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/21/2024] [Accepted: 03/01/2024] [Indexed: 03/06/2024]
Abstract
OBJECTIVES The selected kyotorphin derivatives were tested to improve their antimicrobial and antibiofilm activity. The antimicrobial screening of the KTP derivatives were ascertained in the representative strains of bacteria, including Streptococcus pneumoniae, Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa. METHODS Kyotorphin derivatives, KTP-NH2, KTP-NH2-DL, IbKTP, IbKTP-NH2, MetKTP-DL, MetKTP-LD, were designed and synthesized to improve lipophilicity and resistance to enzymatic degradation. Peptides were synthesized by standard solution or solid-phase peptide synthesis and purified using RP-HPLC, which resulted in >95 % purity, and were fully characterized by mass spectrometry and 1H NMR. The minimum inhibitory concentrations (MIC) determined for bacterial strains were between 20 and 419 μM. The direct effect of IbKTP-NH2 on bacterial cells was imaged using scanning electron microscopy. The absence of toxicity, high survival after infection and an increase in the hemocytes count was evaluated by injections of derivatives in Galleria mellonella larvae. Proteomics analyses of G. mellonella hemolymph were performed to investigate the underlying mechanism of antibacterial activity of IbKTP-NH2 at MIC. RESULTS IbKTP-NH2 induces morphological changes in bacterial cell, many differentially expressed proteins involved in DNA replication, synthesis of cell wall, and virulence were up-regulated after the treatment of G. mellonella with IbKTP-NH2. CONCLUSION We suggest that this derivative, in addition to its physical activity on the bacterial membranes, can elicit a cellular and humoral immune response, therefore, it could be considered for biomedical applications.
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Affiliation(s)
- Vitor M de Andrade
- Laboratório de Bioquímica de Peptídeos, Departamento de Ciência e Tecnologia - Universidade Federal de São Paulo - UNIFESP, Rua Talim, 330, São José dos Campos, SP, 12231-280, Brazil
| | - Vitor D M de Oliveira
- Laboratório de Bioquímica de Peptídeos, Departamento de Ciência e Tecnologia - Universidade Federal de São Paulo - UNIFESP, Rua Talim, 330, São José dos Campos, SP, 12231-280, Brazil
| | - Uilla Barcick
- Laboratório de Proteômica Funcional, Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo - Universidade Federal de São Paulo - UNIFESP, Rua Talim, 330, São José dos Campos, SP, 12231-280, Brazil
| | - Vasanthakumar G Ramu
- Laboratori d'Innovació en Processos i Productes de Síntesi Orgànica (LIPPSO), Departament de Química, Universitat de Girona, Campus Montilivi, 17071, Girona, Spain; Peptides and Complex Generics, #2700, Neovantage, Genome Valley, Shameerpet, Hyderabad, 500078, Telengana, India
| | - Montserrat Heras
- Laboratori d'Innovació en Processos i Productes de Síntesi Orgànica (LIPPSO), Departament de Química, Universitat de Girona, Campus Montilivi, 17071, Girona, Spain
| | - Eduard R Bardají
- Laboratori d'Innovació en Processos i Productes de Síntesi Orgànica (LIPPSO), Departament de Química, Universitat de Girona, Campus Montilivi, 17071, Girona, Spain
| | - Miguel A R B Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028, Lisboa, Portugal
| | - André Zelanis
- Laboratório de Proteômica Funcional, Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo - Universidade Federal de São Paulo - UNIFESP, Rua Talim, 330, São José dos Campos, SP, 12231-280, Brazil
| | - Aline Capella
- Laboratório ProLaser, Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo - UNIFESP, Rua Talim, 330, São José dos Campos, SP, 12231-280, Brazil
| | - Juliana C Junqueira
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, 12245-000, SP, Brazil
| | - Katia Conceição
- Laboratório de Bioquímica de Peptídeos, Departamento de Ciência e Tecnologia - Universidade Federal de São Paulo - UNIFESP, Rua Talim, 330, São José dos Campos, SP, 12231-280, Brazil.
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Moreau J, Noël T, Point K, Tewes F, Deroche L, Clarhaut J, Fitton-Ouhabi V, Perraud E, Marchand S, Buyck JM, Brunet K. Pan-azole-resistant Meyerozyma guilliermondii clonal isolates harbouring a double F126L and L505F mutation in Erg11. Mycoses 2024; 67:e13704. [PMID: 38429226 DOI: 10.1111/myc.13704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/29/2024] [Accepted: 02/02/2024] [Indexed: 03/03/2024]
Abstract
BACKGROUND Meyerozyma guilliermondii is a yeast species responsible for invasive fungal infections. It has high minimum inhibitory concentrations (MICs) to echinocandins, the first-line treatment of candidemia. In this context, azole antifungal agents are frequently used. However, in recent years, a number of azole-resistant strains have been described. Their mechanisms of resistance are currently poorly studied. OBJECTIVE The aim of this study was consequently to understand the mechanisms of azole resistance in several clinical isolates of M. guilliermondii. METHODS Ten isolates of M. guilliermondii and the ATCC 6260 reference strain were studied. MICs of azoles were determined first. Whole genome sequencing of the isolates was then carried out and the mutations identified in ERG11 were expressed in a CTG clade yeast model (C. lusitaniae). RNA expression of ERG11, MDR1 and CDR1 was evaluated by quantitative PCR. A phylogenic analysis was developed and performed on M. guilliermondii isolates. Lastly, in vitro experiments on fitness cost and virulence were carried out. RESULTS Of the ten isolates tested, three showed pan-azole resistance. A combination of F126L and L505F mutations in Erg11 was highlighted in these three isolates. Interestingly, a combination of these two mutations was necessary to confer azole resistance. An overexpression of the Cdr1 efflux pump was also evidenced in one strain. Moreover, the three pan-azole-resistant isolates were shown to be genetically related and not associated with a fitness cost or a lower virulence, suggesting a possible clonal transmission. CONCLUSION In conclusion, this study identified an original combination of ERG11 mutations responsible for pan-azole-resistance in M. guilliermondii. Moreover, we proposed a new MLST analysis for M. guilliermondii that identified possible clonal transmission of pan-azole-resistant strains. Future studies are needed to investigate the distribution of this clone in hospital environment and should lead to the reconsideration of the treatment for this species.
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Affiliation(s)
- Jérémy Moreau
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Thierry Noël
- Université de Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Kévin Point
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Frédéric Tewes
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Luc Deroche
- CHU de Poitiers, Service de Virologie, Poitiers, France
| | - Jonathan Clarhaut
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
- CHU de Poitiers, Service de Toxicologie-Pharmacocinétique, Poitiers, France
| | - Valérie Fitton-Ouhabi
- Université de Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Estelle Perraud
- CHU de Poitiers, Service de Parasitologie et Mycologie Médicale, Poitiers, France
| | - Sandrine Marchand
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
- CHU de Poitiers, Service de Toxicologie-Pharmacocinétique, Poitiers, France
| | - Julien M Buyck
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
| | - Kévin Brunet
- Université de Poitiers, INSERM U1070 PHAR2, Poitiers, France
- CHU de Poitiers, Service de Parasitologie et Mycologie Médicale, Poitiers, France
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6
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Roosen L, Maes D, Musetta L, Himmelreich U. Preclinical Models for Cryptococcosis of the CNS and Their Characterization Using In Vivo Imaging Techniques. J Fungi (Basel) 2024; 10:146. [PMID: 38392818 PMCID: PMC10890286 DOI: 10.3390/jof10020146] [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: 11/30/2023] [Revised: 01/24/2024] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
Infections caused by Cryptococcus neoformans and Cryptococcus gattii remain a challenge to our healthcare systems as they are still difficult to treat. In order to improve treatment success, in particular for infections that have disseminated to the central nervous system, a better understanding of the disease is needed, addressing questions like how it evolves from a pulmonary to a brain disease and how novel treatment approaches can be developed and validated. This requires not only clinical research and research on the microorganisms in a laboratory environment but also preclinical models in order to study cryptococci in the host. We provide an overview of available preclinical models, with particular emphasis on models of cryptococcosis in rodents. In order to further improve the characterization of rodent models, in particular the dynamic aspects of disease manifestation, development, and ultimate treatment, preclinical in vivo imaging methods are increasingly used, mainly in research for oncological, neurological, and cardiac diseases. In vivo imaging applications for fungal infections are rather sparse. A second aspect of this review is how research on models of cryptococcosis can benefit from in vivo imaging methods that not only provide information on morphology and tissue structure but also on function, metabolism, and cellular properties in a non-invasive way.
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Affiliation(s)
- Lara Roosen
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Dries Maes
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Luigi Musetta
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
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7
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Scheler J, Binder U. Alternative in-vivo models of mucormycosis. Front Cell Infect Microbiol 2024; 14:1343834. [PMID: 38362495 PMCID: PMC10867140 DOI: 10.3389/fcimb.2024.1343834] [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: 11/24/2023] [Accepted: 01/16/2024] [Indexed: 02/17/2024] Open
Abstract
Mucormycosis is still regarded a rare fungal infection, but the high incidences of COVID-associated cases in India and other countries have shown its potential threat to large patient cohorts. In addition, infections by these fast-growing fungi are often fatal and cause disfigurement, badly affecting patients' lives. In advancing our understanding of pathogenicity factors involved in this disease, to enhance the diagnostic toolset and to evaluate novel treatment regimes, animal models are indispensable. As ethical and practical considerations typically favor the use of alternative model systems, this review provides an overview of alternative animal models employed for mucormycosis and discusses advantages and limitations of the respective model.
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Affiliation(s)
| | - Ulrike Binder
- Department of Hygiene, Microbiology and Public Health, Division of Hygiene and Medical Microbiology, Medical University Innsbruck, Innsbruck, Tirol, Austria
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Samdavid Thanapaul RJR, Roberds A, Rios KE, Walsh TJ, Bobrov AG. Hyphae of Rhizopus arrhizus and Lichtheimia corymbifera Are More Virulent and Resistant to Antifungal Agents Than Sporangiospores In Vitro and in Galleria mellonella. J Fungi (Basel) 2023; 9:958. [PMID: 37888214 PMCID: PMC10607466 DOI: 10.3390/jof9100958] [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: 08/22/2023] [Revised: 09/14/2023] [Accepted: 09/16/2023] [Indexed: 10/28/2023] Open
Abstract
Mucorales species cause debilitating, life-threatening sinopulmonary diseases in immunocompromised patients and penetrating wounds in trauma victims. Common antifungal agents against mucormycosis have significant toxicity and are often ineffective. To evaluate treatments against mucormycosis, sporangiospores are typically used for in vitro assays and in pre-clinical animal models of pulmonary infections. However, in clinical cases of wound mucormycosis caused by traumatic inoculation, hyphal elements found in soil are likely the form of the inoculated organism. In this study, Galleria mellonella larvae were infected with either sporangiospores or hyphae of Rhizopus arrhizus and Lichtheimia corymbifera. Hyphal infections resulted in greater and more rapid larval lethality than sporangiospores, with an approximate 10-16-fold decrease in LD50 of hyphae for R. arrhizus (p = 0.03) and L. corymbifera (p = 0.001). Liposomal amphotericin B, 10 mg/kg, was ineffective against hyphal infection, while the same dosage was effective against infections produced by sporangiospores. Furthermore, in vitro, antifungal susceptibility studies show that minimum inhibitory concentrations of several antifungal agents against hyphae were higher when compared to those of sporangiospores. These findings support using hyphal elements of Mucorales species for virulence testing and antifungal drug screening in vitro and in G. mellonella for studies of wound mucormycosis.
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Affiliation(s)
- Rex Jeya Rajkumar Samdavid Thanapaul
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (R.J.R.S.T.); (K.E.R.)
- NRC Research Associateship Programs, National Academies of Sciences, Engineering, and Medicine, Washington, DC 20001, USA
| | - Ashleigh Roberds
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (R.J.R.S.T.); (K.E.R.)
| | - Kariana E. Rios
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (R.J.R.S.T.); (K.E.R.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Thomas J. Walsh
- Center for Innovative Therapeutics and Diagnostics, Richmond, VA 23220, USA;
- Department of Medicine and Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Alexander G. Bobrov
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (R.J.R.S.T.); (K.E.R.)
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Vanhoffelen E, Michiels L, Brock M, Lagrou K, Reséndiz-Sharpe A, Vande Velde G. Powerful and Real-Time Quantification of Antifungal Efficacy against Triazole-Resistant and -Susceptible Aspergillus fumigatus Infections in Galleria mellonella by Longitudinal Bioluminescence Imaging. Microbiol Spectr 2023; 11:e0082523. [PMID: 37466453 PMCID: PMC10433797 DOI: 10.1128/spectrum.00825-23] [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: 02/23/2023] [Accepted: 06/27/2023] [Indexed: 07/20/2023] Open
Abstract
Aspergillus fumigatus is an environmental mold that causes life-threatening respiratory infections in immunocompromised patients. The plateaued effectiveness of antifungal therapy and the increasing prevalence of triazole-resistant isolates have led to an urgent need to optimize and expand the current treatment options. For the transition of in vitro research to in vivo models in the time- and resource-consuming preclinical drug development pipeline, Galleria mellonella larvae have been introduced as a valuable in vivo screening intermediate. Despite the high potential of this model, the current readouts of fungal infections in G. mellonella are insensitive, irreproducible, or invasive. To optimize this model, we aimed for the longitudinal quantification of the A. fumigatus burden in G. mellonella using noninvasive bioluminescence imaging (BLI). Larvae were infected with A. fumigatus strains expressing a red-shifted firefly luciferase, and the substrate dosage was optimized for the longitudinal visualization of the fungal burden without affecting larval health. The resulting photon flux was successfully validated for fungal quantification against colony forming units (CFU) analyses, which revealed an increased dynamic range from BLI detection. Comparison of BLI to survival rates and health index scores additionally revealed improved sensitivity for the early discrimination of differences in fungal burdens as early as 1 day after infection. This was confirmed by the improved detection of treatment efficacy against triazole-susceptible and -resistant strains. In conclusion, we established a refined G. mellonella aspergillosis model that enables the noninvasive real-time quantification of A. fumigatus by BLI. This model provides a quick and reproducible in vivo system for the evaluation of treatment options and is in line with 3Rs recommendations. IMPORTANCE Triazole-resistant Aspergillus fumigatus strains are rapidly emerging, and resistant infections are difficult to treat, causing mortality rates of up to 88%. The recent WHO priority list underscores A. fumigatus as one of the most critical fungal pathogens for which innovative antifungal treatment should be (urgently) prioritized. Here, we deliver a Galleria mellonella model for triazole-susceptible and -resistant A. fumigatus infections combined with a statistically powerful quantitative, longitudinal readout of the A. fumigatus burden for optimized preclinical antifungal screening. G. mellonella larvae are a convenient invertebrate model for in vivo antifungal screenings, but so far, the model has been limited by variable and insensitive observational readouts. We show that bioluminescence imaging-based fungal burden quantification outperforms these readouts in reliability, sensitivity, and time to the detection of treatment effects in both triazole-susceptible and -resistant infections and can thus lead to better translatability from in vitro antifungal screening results to in vivo confirmation in mouse and human studies.
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Affiliation(s)
- Eliane Vanhoffelen
- Department of Imaging and Pathology, Biomedical MRI Unit/MoSAIC, KU Leuven, Leuven, Belgium
| | - Lauren Michiels
- Department of Imaging and Pathology, Biomedical MRI Unit/MoSAIC, KU Leuven, Leuven, Belgium
| | - Matthias Brock
- School of Life Sciences, Fungal Biology Group, University of Nottingham, Nottingham, United Kingdom
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Bacteriology and Mycology, KU Leuven, Leuven, Belgium
- Department of Laboratory Medicine, National Reference Center for Mycosis, University Hospitals Leuven, Leuven, Belgium
| | | | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI Unit/MoSAIC, KU Leuven, Leuven, Belgium
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Kaczmarek A, Wrońska AK, Boguś MI. The Changes in Mitochondrial Morphology and Physiology Accompanying Apoptosis in Galleria mellonella (Lepidoptera) Immunocompetent Cells during Conidiobolus coronatus (Entomophthorales) Infection. Int J Mol Sci 2023; 24:10169. [PMID: 37373316 DOI: 10.3390/ijms241210169] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/07/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, their role in insects is not fully understood; thus, more indepth studies of insect cell apoptosis are necessary. The present study investigates mitochondrial involvement during Conidiobolus coronatus-induced apoptosis in Galleria mellonella hemocytes. Previous research has shown that fungal infection could induce apoptosis in insect hemocytes. Our findings indicate that mitochondria undergo several morphological and physiological changes during fungal infection, e.g., loss of mitochondrial membrane potential, megachannel formation, disturbances in intracellular respiration, increased nonrespiratory oxygen consumption in mitochondria, decreased ATP-coupled oxygen consumption and increased non-ATP-coupled oxygen consumption, decreased extracellular and intracellular oxygen consumption, and increased extracellular pH. Our findings confirm that G. mellonella immunocompetent cells demonstrate Ca2+ overload in mitochondria, translocation of cytochrome c-like protein from mitochondrial to cytosol fraction, and higher activation of caspase-9-like protein after C. coronatus infection. Most importantly, several of the changes observed in insect mitochondria are similar to those accompanying apoptosis in mammalian cells, suggesting that the process is evolutionarily conserved.
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Affiliation(s)
- Agata Kaczmarek
- Museum and Institute of Zoology, Polish Academy of Science, Wilcza 64, 00-679 Warsaw, Poland
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Twarda 51/55, 00-875 Warsaw, Poland
| | - Anna Katarzyna Wrońska
- Museum and Institute of Zoology, Polish Academy of Science, Wilcza 64, 00-679 Warsaw, Poland
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Twarda 51/55, 00-875 Warsaw, Poland
| | - Mieczysława Irena Boguś
- Museum and Institute of Zoology, Polish Academy of Science, Wilcza 64, 00-679 Warsaw, Poland
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Twarda 51/55, 00-875 Warsaw, Poland
- Biomibo, 04-872 Warsaw, Poland
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Serrano I, Verdial C, Tavares L, Oliveira M. The Virtuous Galleria mellonella Model for Scientific Experimentation. Antibiotics (Basel) 2023; 12:antibiotics12030505. [PMID: 36978373 PMCID: PMC10044286 DOI: 10.3390/antibiotics12030505] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
The first research on the insect Galleria mellonella was published 85 years ago, and the larva is now widely used as a model to study infections caused by bacterial and fungal pathogens, for screening new antimicrobials, to study the adjacent immune response in co-infections or in host-pathogen interaction, as well as in a toxicity model. The immune system of the G. mellonella model shows remarkable similarities with mammals. Furthermore, results from G. mellonella correlate positively with mammalian models and with other invertebrate models. Unlike other invertebrate models, G. mellonella can withstand temperatures of 37 °C, and its handling and experimental procedures are simpler. Despite having some disadvantages, G. mellonella is a virtuous in vivo model to be used in preclinical studies, as an intermediate model between in vitro and mammalian in vivo studies, and is a great example on how to apply the bioethics principle of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation. This review aims to discuss the progress of the G. mellonella model, highlighting the key aspects of its use, including experimental design considerations and the necessity to standardize them. A different score in the “cocoon” category included in the G. mellonella Health Index Scoring System is also proposed.
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Affiliation(s)
- Isa Serrano
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
- Correspondence:
| | - Cláudia Verdial
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Luís Tavares
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Manuela Oliveira
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
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Antimicrobial Efficacy of Green Synthesized Nanosilver with Entrapped Cinnamaldehyde against Multi-Drug-Resistant Enteroaggregative Escherichia coli in Galleria mellonella. Pharmaceutics 2022; 14:pharmaceutics14091924. [PMID: 36145672 PMCID: PMC9503582 DOI: 10.3390/pharmaceutics14091924] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 12/11/2022] Open
Abstract
The global emergence of antimicrobial resistance (AMR) needs no emphasis. In this study, the in vitro stability, safety, and antimicrobial efficacy of nanosilver-entrapped cinnamaldehyde (AgC) against multi-drug-resistant (MDR) strains of enteroaggregative Escherichia coli (EAEC) were investigated. Further, the in vivo antibacterial efficacy of AgC against MDR-EAEC was also assessed in Galleria mellonella larval model. In brief, UV-Vis and Fourier transform infrared (FTIR) spectroscopy confirmed effective entrapment of cinnamaldehyde with nanosilver, and the loading efficiency was estimated to be 29.50 ± 0.56%. The AgC was of crystalline form as determined by the X-ray diffractogram with a mono-dispersed spherical morphology of 9.243 ± 1.83 nm in electron microscopy. AgC exhibited a minimum inhibitory concentration (MIC) of 0.008−0.016 mg/mL and a minimum bactericidal concentration (MBC) of 0.008−0.032 mg/mL against MDR- EAEC strains. Furthermore, AgC was stable (high-end temperatures, proteases, cationic salts, pH, and host sera) and tested safe for sheep erythrocytes as well as secondary cell lines (RAW 264.7 and HEp-2) with no negative effects on the commensal gut lactobacilli. in vitro, time-kill assays revealed that MBC levels of AgC could eliminate MDR-EAEC infection in 120 min. In G. mellonella larvae, AgC (MBC values) increased survival, decreased MDR-EAEC counts (p < 0.001), had an enhanced immunomodulatory effect, and was tested safe to the host. These findings infer that entrapment enhanced the efficacy of cinnamaldehyde and AgNPs, overcoming their limitations when used individually, indicating AgC as a promising alternative antimicrobial candidate. However, further investigation in appropriate animal models is required to declare its application against MDR pathogens.
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