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Al-Huthaifi AM, Radman BA, Al-Alawi AA, Mahmood F, Liu TB. Mechanisms and Virulence Factors of Cryptococcus neoformans Dissemination to the Central Nervous System. J Fungi (Basel) 2024; 10:586. [PMID: 39194911 DOI: 10.3390/jof10080586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 07/31/2024] [Accepted: 08/15/2024] [Indexed: 08/29/2024] Open
Abstract
Cryptococcosis is a prevalent fungal infection of the central nervous system (CNS) caused by Cryptococcus neoformans, a yeast with a polysaccharide capsule in the basidiomycete group. Normally, C. neoformans infects the respiratory tract and then breaches the blood-brain barrier (BBB), leading to meningitis or meningoencephalitis, which leads to hundreds of thousands of deaths each year. Although the mechanism by which C. neoformans infiltrates the BBB to invade the brain has yet to be fully understood, research has revealed that C. neoformans can cross the BBB using transcellular penetration, paracellular traversal, and infected phagocytes (the "Trojan horse" mechanism). The secretion of multiple virulence factors by C. neoformans is crucial in facilitating the spread of infection after breaching the BBB and causing brain infections. Extensive research has shown that various virulence factors play a significant role in the dissemination of infection beyond the lungs. This review explores the mechanisms of C. neoformans entering the CNS and explains how it bypasses the BBB. Additionally, it aims to understand the interplay between the regulatory mechanisms and virulence factors of C. neoformans.
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Affiliation(s)
| | - Bakeel A Radman
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510315, China
| | | | - Fawad Mahmood
- Medical Research Institute, Southwest University, Chongqing 400715, China
| | - Tong-Bao Liu
- Medical Research Institute, Southwest University, Chongqing 400715, China
- Jinfeng Laboratory, Chongqing 401329, China
- Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing 400715, China
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2
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Evren K, Mutlu-Sarıgüzel F, Koç AN. Cryptococcus neoformans fungemia in a liver transplant patient: Case report and literature review. J Infect Chemother 2024:S1341-321X(24)00219-8. [PMID: 39151551 DOI: 10.1016/j.jiac.2024.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 06/24/2024] [Accepted: 08/13/2024] [Indexed: 08/19/2024]
Abstract
Cryptococcus neoformans is an environmental fungus that can frequently cause life-threatening meningitis and fungemia in acquired immunodeficiency syndrome patients. In recent years, cases of these fungal infections are increasingly identified in HIV-negative patients especially in solid organ transplantation (SOT) patients. Cryptococcal fungemia can often clinically present as life-threatening disseminated disease from subclinical colonization. This is a factor that affects survival, especially in patients with decompensated liver cirrhosis and SOT recipients. Early diagnosis and appropriate treatment are important for the course of the disease. This report describes the cryptococcal fungemia that developed in an HIV-negative patient after SOT due to alcohol-related liver cirrhosis.
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Affiliation(s)
- Kübra Evren
- Department of Medical Microbiology, Başakşehir Çam and Sakura City Hospital, Medical Microbiology, Istanbul, Turkiye.
| | - Fatma Mutlu-Sarıgüzel
- Department of Medical Microbiology, Erciyes University Faculty of Medicine, Kayseri, Turkiye
| | - Ayşe Nedret Koç
- Department of Medical Microbiology, Erciyes University Faculty of Medicine, Kayseri, Turkiye
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3
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Jung KW, Lee SH, Lee KT, Bahn YS. Sensing and responding to host-derived stress signals: lessons from fungal meningitis pathogen. Curr Opin Microbiol 2024; 80:102514. [PMID: 39024914 DOI: 10.1016/j.mib.2024.102514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 06/25/2024] [Accepted: 07/01/2024] [Indexed: 07/20/2024]
Abstract
The sophisticated ability of living organisms to sense and respond to external stimuli is critical for survival. This is particularly true for fungal pathogens, where the capacity to adapt and proliferate within a host is essential. To this end, signaling pathways, whether evolutionarily conserved or unique, have been refined through interactions with the host. Cryptococcus neoformans, an opportunistic fungal pathogen, is responsible for over 190,000 cases and an estimated 147,000 annual deaths globally. Extensive research over the past decades has shed light on the signaling pathways underpinning the pathogenicity of C. neoformans, as well as the host's responses during infection. In this context, we delineate the regulatory mechanisms employed by C. neoformans to detect and react to stresses derived from the host.
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Affiliation(s)
- Kwang-Woo Jung
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Jeonbuk, Republic of Korea
| | - Seung-Heon Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Kyung-Tae Lee
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, Jeonbuk, Republic of Korea.
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea.
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Agrawal R, de Castro RJA, Sturny-Leclère A, Alanio A. Population heterogeneity in Cryptococcus neoformans: Impact on pathogenesis. PLoS Pathog 2024; 20:e1012332. [PMID: 38990818 PMCID: PMC11239025 DOI: 10.1371/journal.ppat.1012332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Affiliation(s)
- Ruchi Agrawal
- Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Translational Mycology Group, Mycology Department, Paris, France
| | - Raffael J Araújo de Castro
- Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Translational Mycology Group, Mycology Department, Paris, France
- Laboratory of Applied Immunology, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasília, Distrito Federal, Brazil
| | - Aude Sturny-Leclère
- Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Translational Mycology Group, Mycology Department, Paris, France
| | - Alexandre Alanio
- Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Translational Mycology Group, Mycology Department, Paris, France
- Mycology-parasitology Laboratory, Hôpital Saint-Louis AP-HP, Paris, France
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5
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Dao A, Kim HY, Garnham K, Kidd S, Sati H, Perfect J, Sorrell TC, Harrison T, Rickerts V, Gigante V, Alastruey-Izquierdo A, Alffenaar JW, Morrissey CO, Chen SCA, Beardsley J. Cryptococcosis-a systematic review to inform the World Health Organization Fungal Priority Pathogens List. Med Mycol 2024; 62:myae043. [PMID: 38935902 PMCID: PMC11210623 DOI: 10.1093/mmy/myae043] [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: 09/11/2023] [Revised: 12/01/2023] [Accepted: 04/27/2024] [Indexed: 06/29/2024] Open
Abstract
Cryptococcosis causes a high burden of disease worldwide. This systematic review summarizes the literature on Cryptococcus neoformans and C. gattii infections to inform the World Health Organization's first Fungal Priority Pathogen List. PubMed and Web of Science were used to identify studies reporting on annual incidence, mortality, morbidity, antifungal resistance, preventability, and distribution/emergence in the past 10 years. Mortality rates due to C. neoformans were 41%-61%. Complications included acute renal impairment, raised intracranial pressure needing shunts, and blindness. There was moderate evidence of reduced susceptibility (MIC range 16-32 mg/l) of C. neoformans to fluconazole, itraconazole, ketoconazole, voriconazole, and amphotericin B. Cryptococcus gattii infections comprised 11%-33% of all cases of invasive cryptococcosis globally. The mortality rates were 10%-23% for central nervous system (CNS) and pulmonary infections, and ∼43% for bloodstream infections. Complications described included neurological sequelae (17%-27% in C. gattii infections) and immune reconstitution inflammatory syndrome. MICs were generally low for amphotericin B (MICs: 0.25-0.5 mg/l), 5-flucytosine (MIC range: 0.5-2 mg/l), itraconazole, posaconazole, and voriconazole (MIC range: 0.06-0.5 mg/l). There is a need for increased surveillance of disease phenotype and outcome, long-term disability, and drug susceptibility to inform robust estimates of disease burden.
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Affiliation(s)
- Aiken Dao
- Sydney Infectious Diseases Institute, The University of Sydney, Sydney, Australia
- Westmead Institute for Medical Research, Westmead, Sydney, Australia
- Westmead Clinical School, Westmead Hospital, Sydney, Australia
| | - Hannah Yejin Kim
- Sydney Infectious Diseases Institute, The University of Sydney, Sydney, Australia
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
- Department of Pharmacy, Westmead Hospital, Westmead, Australia
| | - Katherine Garnham
- Sydney Infectious Diseases Institute, The University of Sydney, Sydney, Australia
- Sunshine Coast University Hospital, Birtinya, Qld 4575, Australia
| | - Sarah Kidd
- National Mycology Reference Centre, Microbiology and Infectious Diseases, SA Pathology, Adelaide, Australia
| | - Hatim Sati
- AMR Division, World Health Organization, Geneva, Switzerland
| | | | - Tania C Sorrell
- Sydney Infectious Diseases Institute, The University of Sydney, Sydney, Australia
- Westmead Institute for Medical Research, Westmead, Sydney, Australia
- Westmead Clinical School, Westmead Hospital, Sydney, Australia
| | - Thomas Harrison
- Institute of Infection and Immunity, St George’s University London, London, UK
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | | | - Valeria Gigante
- AMR Division, World Health Organization, Geneva, Switzerland
| | - Ana Alastruey-Izquierdo
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Jan-Willem Alffenaar
- Sydney Infectious Diseases Institute, The University of Sydney, Sydney, Australia
- Westmead Clinical School, Westmead Hospital, Sydney, Australia
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
| | - C Orla Morrissey
- Department of Infectious Diseases, Alfred Health, Melbourne, Australia
- Monash University, Department of Infectious Diseases, Melbourne, Victoria, Australia
| | - Sharon C-A Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead Hospital, Westmead, Sydney, Australia
| | - Justin Beardsley
- Sydney Infectious Diseases Institute, The University of Sydney, Sydney, Australia
- Westmead Institute for Medical Research, Westmead, Sydney, Australia
- Westmead Clinical School, Westmead Hospital, Sydney, Australia
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G. Mozo E, Ross O, Yuecel R, Dambuza IM, Mukaremera L. Human plasma-like medium (HPLM) induces Cryptococcus neoformans in vivo cell morphologies. mSphere 2024; 9:e0028124. [PMID: 38771036 PMCID: PMC11332328 DOI: 10.1128/msphere.00281-24] [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: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 05/22/2024] Open
Abstract
The fungal pathogen Cryptococcus neoformans (C. neoformans) forms yeast cells of different sizes and morphological characteristics during infection. These features are usually not seen in standard laboratory in vitro conditions. Here, we describe in vivo cell morphologies when C. neoformans is grown in human plasma-like medium at 37°C, 5% CO2. We observed mixed-size populations of cells less than 1 µm up to 16.8 µm in cell diameter, increased capsule size, high chitin, and DNA content in larger cells. Our findings show that serum is not required for human plasma-like medium (HPLM)-induced C. neoformans cellular heterogeneity. Thus, this new method offers an opportunity to investigate factors of C. neoformans that mediate pathogenesis or host-pathogen interactions in a physiologically relevant setting.IMPORTANCEWe provide a description of new in vitro culture condition using the human plasma-like medium that supports the formation of the full range of in vivo cell morphologies of C. neoformans.
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Affiliation(s)
- Eduardo G. Mozo
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Orlando Ross
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Raif Yuecel
- Faculty of Health and Life Sciences, Exeter Centre for Cytomics, The Bioeconomy Centre, University of Exeter, Exeter, United Kingdom
| | - Ivy M. Dambuza
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Liliane Mukaremera
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
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Jafarlou M. Unveiling the menace: a thorough review of potential pandemic fungal disease. FRONTIERS IN FUNGAL BIOLOGY 2024; 5:1338726. [PMID: 38711422 PMCID: PMC11071163 DOI: 10.3389/ffunb.2024.1338726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/04/2024] [Indexed: 05/08/2024]
Abstract
Fungal diseases have emerged as a significant global health threat, with the potential to cause widespread outbreaks and significant morbidity and mortality. Anticipating future pandemic fungal diseases is essential for effective preparedness and response strategies. This comprehensive literature review aims to provide a comprehensive analysis of the existing research on this topic. Through an extensive examination of scholarly articles, this review identifies potential fungal pathogens that have the potential to become pandemics in the future. It explores the factors contributing to the emergence and spread of these fungal diseases, including climate change, globalization, and antimicrobial resistance. The review also discusses the challenges in diagnosing and treating these diseases, including limited access to diagnostic tools and antifungal therapies. Furthermore, it examines the strategies and interventions that can be employed to mitigate the impact of future pandemic fungal diseases, such as improved surveillance systems, public health education, and research advancements. The findings of this literature review contribute to our understanding of the potential risks posed by fungal diseases and provide valuable insights for public health professionals and policymakers in effectively preparing for and responding to future pandemic outbreaks. Overall, this review emphasizes the importance of proactive measures and collaborative efforts to anticipate and mitigate the impact of future pandemic fungal diseases.
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Yang Z, Wang X, Dong T, Zhao WJ, Li H. Impact of glucocorticoids and rapamycin on autophagy in Candida glabrata-infected macrophages from BALB/c mice. Front Immunol 2024; 15:1367048. [PMID: 38585259 PMCID: PMC10995521 DOI: 10.3389/fimmu.2024.1367048] [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: 01/08/2024] [Accepted: 02/19/2024] [Indexed: 04/09/2024] Open
Abstract
Objective In the defense against microorganisms like Candida albicans, macrophages recruit LC3(Microtubule-associated protein 1A/1B-light chain 3) to the periplasm, engaging in the elimination process through the formation of a single-membrane phagosome known as LC3-associated phagocytosis (LAP). Building on this, we propose the hypothesis that glucocorticoids may hinder macrophage phagocytosis of Candida glabrata by suppressing LAP, and rapamycin could potentially reverse this inhibitory effect. Methods RAW264.7 cells were employed for investigating the immune response to Candida glabrata infection. Various reagents, including dexamethasone, rapamycin, and specific antibodies, were utilized in experimental setups. Assays, such as fluorescence microscopy, flow cytometry, ELISA (Enzyme-Linked Immunosorbent Assay), Western blot, and confocal microscopy, were conducted to assess phagocytosis, cytokine levels, protein expression, viability, and autophagy dynamics. Results Glucocorticoids significantly inhibited macrophage autophagy, impairing the cells' ability to combat Candida glabrata. Conversely, rapamycin exhibited a dual role, initially inhibiting and subsequently promoting phagocytosis of Candida glabrata by macrophages. Glucocorticoids hinder macrophage autophagy in Candida glabrata infection by suppressing the MTOR pathway(mammalian target of rapamycin pathway), while the activation of MTOR pathway by Candida glabrata diminishes over time. Conclusion Our study elucidates the intricate interplay between glucocorticoids, rapamycin, and macrophage autophagy during Candida glabrata infection. Understanding the implications of these interactions not only sheds light on the host immune response dynamics but also unveils potential therapeutic avenues for managing fungal infections.
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Affiliation(s)
| | | | | | | | - Hongbin Li
- Department of Dermatology and Venereology, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
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9
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Mbangiwa T, Sturny-Leclère A, Lechiile K, Kajanga C, Boyer-Chammard T, Hoving JC, Leeme T, Moyo M, Youssouf N, Lawrence DS, Mwandumba H, Mosepele M, Harrison TS, Jarvis JN, Lortholary O, Alanio A. Development and validation of quantitative PCR assays for HIV-associated cryptococcal meningitis in sub-Saharan Africa: a diagnostic accuracy study. THE LANCET. MICROBE 2024; 5:e261-e271. [PMID: 38342110 PMCID: PMC10914677 DOI: 10.1016/s2666-5247(23)00362-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 09/27/2023] [Accepted: 10/26/2023] [Indexed: 02/13/2024]
Abstract
BACKGROUND HIV-associated cryptococcal meningitis is the second leading cause of AIDS-related deaths, with a 10-week mortality rate of 25-30%. Fungal load assessed by colony-forming unit (CFU) counts is used as a prognostic marker and to monitor response to treatment in research studies. PCR-based assessment of fungal load could be quicker and less labour-intensive. We sought to design, optimise, and validate quantitative PCR (qPCR) assays for the detection, identification, and quantification of Cryptococcus infections in patients with cryptococcal meningitis in sub-Saharan Africa. METHODS We developed and validated species-specific qPCR assays based on DNA amplification of QSP1 (QSP1A specific to Cryptococcus neoformans, QSP1B/C specific to Cryptococcus deneoformans, and QSP1D specific to Cryptococcus gattii species) and a pan-Cryptococcus assay based on a multicopy 28S rRNA gene. This was a longitudinal study that validated the designed assays on cerebrospinal fluid (CSF) of 209 patients with cryptococcal meningitis at baseline (day 0) and during anti-fungal therapy (day 7 and day 14), from the AMBITION-cm trial in Botswana and Malawi (2018-21). Eligible patients were aged 18 years or older and presenting with a first case of cryptococcal meningitis. FINDINGS When compared with quantitative cryptococcal culture as the reference, the sensitivity of the 28S rRNA was 98·2% (95% CI 95·1-99·5) and of the QSP1 assay was 90·4% (85·2-94·0) in CSF at day 0. Quantification of the fungal load with QSP1 and 28S rRNA qPCR correlated with quantitative cryptococcal culture (R2=0·73 and R2=0·78, respectively). Both Botswana and Malawi had a predominant C neoformans prevalence of 67% (95% CI 55-75) and 68% (57-73), respectively, and lower C gattii rates of 21% (14-31) and 8% (4-14), respectively. We identified ten patients that, after 14 days of treatment, harboured viable but non-culturable yeasts based on QSP1 RNA detection (without any positive CFU in CSF culture). INTERPRETATION QSP1 and 28S rRNA assays are useful in identifying Cryptococcus species. qPCR results correlate well with baseline quantitative cryptococcal culture and show a similar decline in fungal load during induction therapy. These assays could be a faster alternative to quantitative cryptococcal culture to determine fungal load clearance. The clinical implications of the possible detection of viable but non-culturable cells in CSF during induction therapy remain unclear. FUNDING European and Developing Countries Clinical Trials Partnership; Swedish International Development Cooperation Agency; Wellcome Trust/UK Medical Research Council/UKAID Joint Global Health Trials; and UK National Institute for Health Research.
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Affiliation(s)
- Tshepiso Mbangiwa
- Botswana-Harvard Health Partnership, Gaborone, Botswana; Institut Pasteur, Université Paris Cité, Translational Mycology Group, Centre National de Référence Mycoses Invasives et Antifongiques, Department of Mycology, Paris, France; Institute of Infectious Disease and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Aude Sturny-Leclère
- Institut Pasteur, Université Paris Cité, Translational Mycology Group, Centre National de Référence Mycoses Invasives et Antifongiques, Department of Mycology, Paris, France
| | | | - Cheusisime Kajanga
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Kamuzu University of Health Science, Blantyre, Malawi
| | - Timothée Boyer-Chammard
- Institut Pasteur, Université Paris Cité, Translational Mycology Group, Centre National de Référence Mycoses Invasives et Antifongiques, Department of Mycology, Paris, France; Department of Infectious Diseases and Tropical Medicine, Centre Hospitalier d'Ajaccio, Ajaccio, France
| | - Jennifer C Hoving
- Institute of Infectious Disease and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; AFRICA CMM Medical Mycology Research Unit, Institute of Infectious Disease and Molecular Medicine (IDM), Cape Town, South Africa
| | - Tshepo Leeme
- Botswana-Harvard Health Partnership, Gaborone, Botswana
| | - Melanie Moyo
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Kamuzu University of Health Science, Blantyre, Malawi
| | - Nabila Youssouf
- Botswana-Harvard Health Partnership, Gaborone, Botswana; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - David S Lawrence
- Botswana-Harvard Health Partnership, Gaborone, Botswana; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Henry Mwandumba
- Institute of Infectious Disease and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Liverpool School of Tropical Medicine, Liverpool, UK
| | - Mosepele Mosepele
- Botswana-Harvard Health Partnership, Gaborone, Botswana; Department of Internal Medicine, University of Botswana, Gaborone, Botswana
| | - Thomas S Harrison
- Centre for Global Health, Institute for Infection and Immunity, St George's University of London, London, UK; Clinical Academic Group in Infection, St George's University Hospitals NHS Foundation Trust, London, UK; MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Joseph N Jarvis
- Botswana-Harvard Health Partnership, Gaborone, Botswana; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Olivier Lortholary
- Institut Pasteur, Université Paris Cité, Translational Mycology Group, Centre National de Référence Mycoses Invasives et Antifongiques, Department of Mycology, Paris, France; Necker Pasteur Centre for Infectious Diseases and Tropical Médicine, Hôpital Universitaire Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Alexandre Alanio
- Institut Pasteur, Université Paris Cité, Translational Mycology Group, Centre National de Référence Mycoses Invasives et Antifongiques, Department of Mycology, Paris, France; Laboratoire de parasitologie-mycologie, AP-HP, Hôpital Saint-Louis, F-75010, Paris, France.
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10
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Ke W, Xie Y, Chen Y, Ding H, Ye L, Qiu H, Li H, Zhang L, Chen L, Tian X, Shen Z, Song Z, Fan X, Zong JF, Guo Z, Ma X, Xiao M, Liao G, Liu CH, Yin WB, Dong Z, Yang F, Jiang YY, Perlin DS, Chen Y, Fu YV, Wang L. Fungicide-tolerant persister formation during cryptococcal pulmonary infection. Cell Host Microbe 2024; 32:276-289.e7. [PMID: 38215741 DOI: 10.1016/j.chom.2023.12.012] [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: 06/08/2023] [Revised: 09/25/2023] [Accepted: 12/14/2023] [Indexed: 01/14/2024]
Abstract
Bacterial persisters, a subpopulation of genetically susceptible cells that are normally dormant and tolerant to bactericides, have been studied extensively because of their clinical importance. In comparison, much less is known about the determinants underlying fungicide-tolerant fungal persister formation in vivo. Here, we report that during mouse lung infection, Cryptococcus neoformans forms persisters that are highly tolerant to amphotericin B (AmB), the standard of care for treating cryptococcosis. By exploring stationary-phase indicator molecules and developing single-cell tracking strategies, we show that in the lung, AmB persisters are enriched in cryptococcal cells that abundantly produce stationary-phase molecules. The antioxidant ergothioneine plays a specific and key role in AmB persistence, which is conserved in phylogenetically distant fungi. Furthermore, the antidepressant sertraline (SRT) shows potent activity specifically against cryptococcal AmB persisters. Our results provide evidence for and the determinant of AmB-tolerant persister formation in pulmonary cryptococcosis, which has potential clinical significance.
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Affiliation(s)
- Weixin Ke
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuyan Xie
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingying Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Ding
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Leixin Ye
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haoning Qiu
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hao Li
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Lanyue Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiuyun Tian
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhenghao Shen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zili Song
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Fan
- Department of Infectious Diseases and Clinical Microbiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Jian-Fa Zong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhengyan Guo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoyu Ma
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Meng Xiao
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing 100730, China
| | - Guojian Liao
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Cui Hua Liu
- University of Chinese Academy of Sciences, Beijing 100049, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Feng Yang
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Yuan-Ying Jiang
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Yihua Chen
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu V Fu
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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11
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Hommel B, Sturny-Leclère A, Alanio A. In Vitro Titan Cell Generation in Cryptococcus neoformans and Automated Cell Size Measurements. Methods Mol Biol 2024; 2775:385-391. [PMID: 38758332 DOI: 10.1007/978-1-0716-3722-7_26] [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: 05/18/2024]
Abstract
A special feature of the human fungal pathogen Cryptococcus neoformans is its morphological changes triggered by the interaction with the host. During infection, a specific increase in cell size is observed, particularly in lung tissue, from a typical cell size of 5-7 μm cells to cells larger than 10 μm, dubbed titan cells (TCs). However, the study of this specific cell subpopulation was, until now, only possible via recovery of TCs from lungs of mice during experimental infections where stable and reproducible generation of TCs occurs.The protocol described here generates TCs using in vitro conditions and measures cell size using a rapid, automated method. TC generation in vitro is robust and reproducible, generating yeast cells harboring the same characteristics of TCs generated in vivo.
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Affiliation(s)
- Benjamin Hommel
- Translational Mycology Research Group, Institut Pasteur, Université Paris Cité, Centre National de Référence Mycoses Invasives et Antifongiques, Département de Mycologie, Paris, France
| | - Aude Sturny-Leclère
- Institut Pasteur, Université Paris Cité,National Reference Center for Invasive Mycoses and Antifungals, Paris, France
| | - Alexandre Alanio
- Translational Mycology Research Group, Institut Pasteur, Université Paris Cité, Centre National de Référence Mycoses Invasives et Antifongiques, Département de Mycologie, Paris, France.
- Laboratoire de parasitologie-mycologie, AP-HP, Hôpital Saint-Louis, Paris, France.
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12
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Agrawal R, Sturny-Leclère A, de Castro RJA, Alanio A. Induction of Dormancy in Cryptococcus neoformans In Vitro: The HypNOS Protocol. Methods Mol Biol 2024; 2775:349-358. [PMID: 38758328 DOI: 10.1007/978-1-0716-3722-7_22] [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: 05/18/2024]
Abstract
Cryptococcus neoformans is the second major cause of death in patients with HIV. During a latent infection, this pathogenic fungus survives in the host for years without causing symptoms of active disease. Upon favorable conditions, such as immunosuppression due to HIV infection, or other conditions (steroid use or organ transplantation), the yeast may reactivate and cause active cryptococcosis. Hence, dormancy is an important phase in the pathogenesis of C. neoformans. Additionally, C. neoformans also persists during antifungal treatment and causes disease recurrence, which is a major medical problem, especially in low- and middle-income countries. To survive in the host, yeast cells must react to the stresses they are exposed to and generate a cellular response that is favorable for yeast survival. A prominent strategy used by C. neoformans to combat challenging surroundings is dormancy, which may translate into a viable, but nonculturable phenotype (VBNC). This chapter describes an in vitro protocol to generate and characterize dormant Cryptococci.
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Affiliation(s)
- Ruchi Agrawal
- Department of Mycology, Translational Mycology Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Paris, France
| | - Aude Sturny-Leclère
- Department of Mycology, Translational Mycology Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Paris, France
| | - Raffael J A de Castro
- Department of Mycology, Translational Mycology Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Paris, France
| | - Alexandre Alanio
- Department of Mycology, Translational Mycology Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Paris, France.
- Laboratoire de parrasitologie-Mycologie, Hôpital Saint-Louis, Paris, France.
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13
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Lafont E, Sturny-Leclère A, Coelho C, Lanternier F, Alanio A. Assessing Phagocytosis of Cryptococcus neoformans Cells in Human Monocytes or the J774 Murine Macrophage Cell Line. Methods Mol Biol 2024; 2775:157-169. [PMID: 38758317 DOI: 10.1007/978-1-0716-3722-7_11] [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: 05/18/2024]
Abstract
Monocyte/macrophage cells play a central role in innate immunity against C. neoformans and C. gattii, species known to cause human disease. Cryptococcus is the only fungal genus known to possess such a large extracellular polysaccharide capsule, which impacts interactions of innate cells with the yeast. This interaction results in different fates, such as phagocytosis and intracellular proliferation and, as the interaction progresses, vomocytosis, cell-to-cell transfer, lysis of macrophages, or yeast killing. Differentiating internalized versus external Cryptococcus cells is thus essential to evaluate monocyte-macrophage phagocytosis. We describe here a protocol that allows quantification of Cryptococcus spp. phagocytosis using quantitative flow cytometry in human monocytes and a murine macrophage cell line (J774).
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Affiliation(s)
- Emmanuel Lafont
- Translational Mycology Research Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Paris, France
| | - Aude Sturny-Leclère
- Department of Mycology, Translational Mycology Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Paris, France
| | - Carolina Coelho
- MRC Centre for Medical Mycology, College of Health and Medicine, University of Exeter, Exeter, Devon, UK
| | - Fanny Lanternier
- Translational Mycology Research Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Paris, France
- MRC Centre for Medical Mycology, College of Health and Medicine, University of Exeter, Exeter, Devon, UK
- Service de maladies infectieuses et tropicales, hôpital Necker-Enfants Malades, Paris, France
| | - Alexandre Alanio
- Translational Mycology Research Group, Institut Pasteur, Université Paris Cité, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Paris, France.
- Laboratoire de parasitologie-mycologie, AP-HP, Hôpital Saint-Louis, Paris, France.
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14
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Alanazi AH, Chastain DB, Rudraraju M, Parvathagiri V, Shan S, Lin X, Henao-Martínez AF, Franco-Paredes C, Narayanan SP, Somanath PR. A multi-arm, parallel, preclinical study investigating the potential benefits of acetazolamide, candesartan, and triciribine in combination with fluconazole for the treatment of cryptococcal meningoencephalitis. Eur J Pharmacol 2023; 960:176177. [PMID: 37931839 PMCID: PMC10985624 DOI: 10.1016/j.ejphar.2023.176177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/08/2023]
Abstract
Cryptococcus neoformans, an opportunistic fungal pathogen, primarily infects immunodeficient patients frequently causing cryptococcal meningoencephalitis (CM). Increased intracranial pressure (ICP) is a serious complication responsible for increased morbidity and mortality in CM patients. Non-invasive pharmacological agents that mitigate ICP could be beneficial in treating CM patients. The objective of the study was to investigate the efficacy of acetazolamide (AZA), candesartan (CAN), and triciribine (TCBN), in combination with the antifungal fluconazole, on C. neoformans-induced endothelial, brain, and lung injury in an experimental mouse model of CM. Our study shows that C. neoformans increases the expression of brain endothelial cell (BEC) junction proteins Claudin-5 (Cldn5) and VE-Cadherin to induce pathological cell-barrier remodeling and gap formation associated with increased Akt and p38 MAPK activation. All three agents inhibited C. neoformans-induced endothelial gap formation, only CAN and TCBN significantly reduced C. neoformans-induced Cldn5 expression, and only TCBN was effective in inhibiting Akt and p38MAPK. Interestingly, although C. neoformans did not cause brain or lung edema in mice, it induced lung and brain injuries, which were significantly reversed by AZA, CAN, or TCBN. Our study provides novel insights into the direct effects of C. neoformans on BECs in vitro, and the potential benefits of using AZA, CAN, or TCBN in the management of CM patients.
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Affiliation(s)
- Abdulaziz H Alanazi
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30907, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, 30901, USA
| | - Daniel B Chastain
- Department of Clinical and Administrative Pharmacy, University of Georgia College of Pharmacy, SWGA Clinical Campus, Phoebe Putney Memorial Hospital, Albany, GA, 31701, USA
| | - Madhuri Rudraraju
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30907, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, 30901, USA
| | - Varun Parvathagiri
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30907, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, 30901, USA
| | - Shengshuai Shan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30907, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, 30901, USA
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Andrés F Henao-Martínez
- Division of Infectious Diseases, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Carlos Franco-Paredes
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, 80523, USA; Hospital Infantil de México, Federico Gómez, México City, 06720, Mexico
| | - S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30907, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, 30901, USA
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30907, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, 30901, USA.
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15
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de Castro RJA, Marina CL, Sturny-Leclère A, Hoffmann C, Bürgel PH, Wong SSW, Aimanianda V, Varet H, Agrawal R, Bocca AL, Alanio A. Kicking sleepers out of bed: Macrophages promote reactivation of dormant Cryptococcus neoformans by extracellular vesicle release and non-lytic exocytosis. PLoS Pathog 2023; 19:e1011841. [PMID: 38033163 PMCID: PMC10715671 DOI: 10.1371/journal.ppat.1011841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/12/2023] [Accepted: 11/18/2023] [Indexed: 12/02/2023] Open
Abstract
Macrophages play a key role in disseminated cryptococcosis, a deadly fungal disease caused by Cryptococcus neoformans. This opportunistic infection can arise following the reactivation of a poorly characterized latent infection attributed to dormant C. neoformans. Here, we investigated the mechanisms underlying reactivation of dormant C. neoformans using an in vitro co-culture model of viable but non-culturable (VBNC; equivalent of dormant) yeast cells with bone marrow-derived murine macrophages (BMDMs). Comparative transcriptome analysis of BMDMs incubated with log, stationary phase or VBNC cells of C. neoformans showed that VBNC cells elicited a reduced transcriptional modification of the macrophage but retaining the ability to regulate genes important for immune response, such as NLRP3 inflammasome-related genes. We further confirmed the maintenance of the low immunostimulatory capacity of VBNC cells using multiplex cytokine profiling, and analysis of cell wall composition and dectin-1 ligands exposure. In addition, we evaluated the effects of classic (M1) or alternative (M2) macrophage polarization on VBNC cells. We observed that intracellular residence sustained dormancy, regardless of the polarization state of macrophages and despite indirect detection of pantothenic acid (or its derivatives), a known reactivator for VBNC cells, in the C. neoformans-containing phagolysosome. Notably, M0 and M2, but not M1 macrophages, induced extracellular reactivation of VBNC cells by the secretion of extracellular vesicles and non-lytic exocytosis. Our results indicate that VBNC cells retain the low immunostimulatory profile required for persistence of C. neoformans in the host. We also describe a pro-pathogen role of macrophage-derived extracellular vesicles in C. neoformans infection and reinforce the impact of non-lytic exocytosis and the macrophage profile on the pathophysiology of cryptococcosis.
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Affiliation(s)
- Raffael Júnio Araújo de Castro
- Translational Mycology Research Group, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Institut Pasteur, Université Paris Cité, Paris, France
- Laboratory of Applied Immunology, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasília, Distrito Federal, Brazil
| | - Clara Luna Marina
- Laboratory of Applied Immunology, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasília, Distrito Federal, Brazil
| | - Aude Sturny-Leclère
- Translational Mycology Research Group, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Institut Pasteur, Université Paris Cité, Paris, France
| | - Christian Hoffmann
- Food Research Center, Department of Food Sciences and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Pedro Henrique Bürgel
- Laboratory of Applied Immunology, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasília, Distrito Federal, Brazil
| | - Sarah Sze Wah Wong
- Immunobiology of Aspergillus, Institut Pasteur, Université Paris Cité, Paris, France
| | - Vishukumar Aimanianda
- Immunobiology of Aspergillus, Institut Pasteur, Université Paris Cité, Paris, France
| | - Hugo Varet
- Plate-forme Technologique Biomics, Institut Pasteur, Université Paris Cité, Paris, France
| | - Ruchi Agrawal
- Translational Mycology Research Group, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Institut Pasteur, Université Paris Cité, Paris, France
| | - Anamélia Lorenzetti Bocca
- Laboratory of Applied Immunology, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasília, Distrito Federal, Brazil
| | - Alexandre Alanio
- Translational Mycology Research Group, National Reference Center for Invasive Mycoses and Antifungals, Mycology Department, Institut Pasteur, Université Paris Cité, Paris, France
- Laboratoire de parasitologie-mycologie, AP-HP, Hôpital Saint-Louis, Paris, France
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16
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Proctor DM, Drummond RA, Lionakis MS, Segre JA. One population, multiple lifestyles: Commensalism and pathogenesis in the human mycobiome. Cell Host Microbe 2023; 31:539-553. [PMID: 37054674 PMCID: PMC10155287 DOI: 10.1016/j.chom.2023.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/12/2023] [Accepted: 02/23/2023] [Indexed: 04/15/2023]
Abstract
Candida auris and Candida albicans can result in invasive fungal diseases. And yet, these species can stably and asymptomatically colonize human skin and gastrointestinal tracts. To consider these disparate microbial lifestyles, we first review factors shown to influence the underlying microbiome. Structured by the damage response framework, we then consider the molecular mechanisms deployed by C. albicans to switch between commensal and pathogenic lifestyles. Next, we explore this framework with C. auris to highlight how host physiology, immunity, and/or antibiotic receipt are associated with progression from colonization to infection. While treatment with antibiotics increases the risk that an individual will succumb to invasive candidiasis, the underlying mechanisms remain unclear. Here, we describe several hypotheses that may explain this phenomenon. We conclude by highlighting future directions integrating genomics with immunology to advance our understanding of invasive candidiasis and human fungal disease.
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Affiliation(s)
- Diana M Proctor
- Microbial Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Rebecca A Drummond
- Institute of Immunology & Immunotherapy, Institute of Microbiology & Infection, University of Birmingham, Birmingham B15 2TT, UK
| | - Michail S Lionakis
- Fungal Pathogenesis Section, Laboratory of Clinical Immunology and Microbiology (LCIM), National Institute of Allergy & Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Julia A Segre
- Microbial Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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17
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Telzrow CL, Esher Righi S, Cathey JM, Granek JA, Alspaugh JA. Cryptococcus neoformans Mar1 function links mitochondrial metabolism, oxidative stress, and antifungal tolerance. Front Physiol 2023; 14:1150272. [PMID: 36969606 PMCID: PMC10033685 DOI: 10.3389/fphys.2023.1150272] [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: 01/23/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023] Open
Abstract
Introduction: Microbial pathogens undergo significant physiological changes during interactions with the infected host, including alterations in metabolism and cell architecture. The Cryptococcus neoformans Mar1 protein is required for the proper ordering of the fungal cell wall in response to host-relevant stresses. However, the precise mechanism by which this Cryptococcus-specific protein regulates cell wall homeostasis was not defined. Methods: Here, we use comparative transcriptomics, protein localization, and phenotypic analysis of a mar1D loss-of-function mutant strain to further define the role of C. neoformans Mar1 in stress response and antifungal resistance. Results: We demonstrate that C. neoformans Mar1 is highly enriched in mitochondria. Furthermore, a mar1Δ mutant strain is impaired in growth in the presence of select electron transport chain inhibitors, has altered ATP homeostasis, and promotes proper mitochondrial morphogenesis. Pharmacological inhibition of complex IV of the electron transport chain in wild-type cells promotes similar cell wall changes as the mar1Δ mutant strain, supporting prior associations between mitochondrial function and cell wall homeostasis. Although Mar1 is not required for general susceptibility to the azole antifungals, the mar1Δ mutant strain displays increased tolerance to fluconazole that correlates with repressed mitochondrial metabolic activity. Discussion: Together, these studies support an emerging model in which the metabolic activity of microbial cells directs cell physiological changes to allow persistence in the face of antimicrobial and host stress.
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Affiliation(s)
- Calla L. Telzrow
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, United States
| | - Shannon Esher Righi
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Jackson M. Cathey
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States
| | - Joshua A. Granek
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, United States
| | - J. Andrew Alspaugh
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, United States
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18
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19
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Sephton-Clark P, Tenor JL, Toffaletti DL, Meyers N, Giamberardino C, Molloy SF, Palmucci JR, Chan A, Chikaonda T, Heyderman R, Hosseinipour M, Kalata N, Kanyama C, Kukacha C, Lupiya D, Mwandumba HC, Harrison T, Bicanic T, Perfect JR, Cuomo CA. Genomic Variation across a Clinical Cryptococcus Population Linked to Disease Outcome. mBio 2022; 13:e0262622. [PMID: 36354332 PMCID: PMC9765290 DOI: 10.1128/mbio.02626-22] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/13/2022] [Indexed: 11/12/2022] Open
Abstract
Cryptococcus neoformans is the causative agent of cryptococcosis, a disease with poor patient outcomes that accounts for approximately 180,000 deaths each year. Patient outcomes may be impacted by the underlying genetics of the infecting isolate; however, our current understanding of how genetic diversity contributes to clinical outcomes is limited. Here, we leverage clinical, in vitro growth and genomic data for 284 C. neoformans isolates to identify clinically relevant pathogen variants within a population of clinical isolates from patients with human immunodeficiency virus (HIV)-associated cryptococcosis in Malawi. Through a genome-wide association study (GWAS) approach, we identify variants associated with the fungal burden and the growth rate. We also find both small and large-scale variation, including aneuploidy, associated with alternate growth phenotypes, which may impact the course of infection. Genes impacted by these variants are involved in transcriptional regulation, signal transduction, glycosylation, sugar transport, and glycolysis. We show that growth within the central nervous system (CNS) is reliant upon glycolysis in an animal model and likely impacts patient mortality, as the CNS yeast burden likely modulates patient outcome. Additionally, we find that genes with roles in sugar transport are enriched in regions under selection in specific lineages of this clinical population. Further, we demonstrate that genomic variants in two genes identified by GWAS impact virulence in animal models. Our approach identifies links between the genetic variation in C. neoformans and clinically relevant phenotypes and animal model pathogenesis, thereby shedding light on specific survival mechanisms within the CNS and identifying the pathways involved in yeast persistence. IMPORTANCE Infection outcomes for cryptococcosis, most commonly caused by C. neoformans, are influenced by host immune responses as well as by host and pathogen genetics. Infecting yeast isolates are genetically diverse; however, we lack a deep understanding of how this diversity impacts patient outcomes. To better understand both clinical isolate diversity and how diversity contributes to infection outcomes, we utilize a large collection of clinical C. neoformans samples that were isolated from patients enrolled in a clinical trial across 3 hospitals in Malawi. By combining whole-genome sequence data, clinical data, and in vitro growth data, we utilize genome-wide association approaches to examine the genetic basis of virulence. Genes with significant associations display virulence attributes in both murine and rabbit models, demonstrating that our approach can identify potential links between genetic variants and patho-biologically significant phenotypes.
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Affiliation(s)
- Poppy Sephton-Clark
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Jennifer L. Tenor
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Dena L. Toffaletti
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Nancy Meyers
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Charles Giamberardino
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Síle F. Molloy
- Centre for Global Health, Institute of Infection and Immunity, St George's University of London, London, United Kingdom
- Clinical Academic Group in Infection, St George's University Hospital, London, United Kingdom
| | - Julia R. Palmucci
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Adrienne Chan
- Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Tarsizio Chikaonda
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Robert Heyderman
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Mina Hosseinipour
- UNC Project Malawi, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Newton Kalata
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Cecilia Kanyama
- UNC Project Malawi, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Christopher Kukacha
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Duncan Lupiya
- Tisungane Clinic, Zomba Central Hospital, Zomba, Malawi
| | - Henry C. Mwandumba
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Thomas Harrison
- Centre for Global Health, Institute of Infection and Immunity, St George's University of London, London, United Kingdom
- Clinical Academic Group in Infection, St George's University Hospital, London, United Kingdom
| | - Tihana Bicanic
- Centre for Global Health, Institute of Infection and Immunity, St George's University of London, London, United Kingdom
- Clinical Academic Group in Infection, St George's University Hospital, London, United Kingdom
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Christina A. Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
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20
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de Castro RJA, Rêgo MTAM, Brandão FS, Pérez ALA, De Marco JL, Poças-Fonseca MJ, Nichols C, Alspaugh JA, Felipe MSS, Alanio A, Bocca AL, Fernandes L. Engineered Fluorescent Strains of Cryptococcus neoformans: a Versatile Toolbox for Studies of Host-Pathogen Interactions and Fungal Biology, Including the Viable but Nonculturable State. Microbiol Spectr 2022; 10:e0150422. [PMID: 36005449 PMCID: PMC9603711 DOI: 10.1128/spectrum.01504-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/05/2022] [Indexed: 12/31/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen known for its remarkable ability to infect and subvert phagocytes. This ability provides survival and persistence within the host and relies on phenotypic plasticity. The viable but nonculturable (VBNC) phenotype was recently described in C. neoformans, whose study is promising in understanding the pathophysiology of cryptococcosis. The use of fluorescent strains is improving host interaction research, but it is still underexploited. Here, we fused histone H3 or the poly(A) binding protein (Pab) to enhanced green fluorescent protein (eGFP) or mCherry, obtaining a set of C. neoformans transformants with different colors, patterns of fluorescence, and selective markers (hygromycin B resistance [Hygr] or neomycin resistance [Neor]). We validated their similarity to the parental strain in the stress response, the expression of virulence-related phenotypes, mating, virulence in Galleria mellonella, and survival within murine macrophages. PAB-GFP, the brightest transformant, was successfully applied for the analysis of phagocytosis by flow cytometry and fluorescence microscopy. Moreover, we demonstrated that an engineered fluorescent strain of C. neoformans was able to generate VBNC cells. GFP-tagged Pab1, a key regulator of the stress response, evidenced nuclear retention of Pab1 and the assembly of cytoplasmic stress granules, unveiling posttranscriptional mechanisms associated with dormant C. neoformans cells. Our results support that the PAB-GFP strain is a useful tool for research on C. neoformans. IMPORTANCE Cryptococcus neoformans is a human-pathogenic yeast that can undergo a dormant state and is responsible for over 180,000 deaths annually worldwide. We engineered a set of fluorescent transformants to aid in research on C. neoformans. A mutant with GFP-tagged Pab1 improved fluorescence-based techniques used in host interaction studies. Moreover, this mutant induced a viable but nonculturable phenotype and uncovered posttranscriptional mechanisms associated with dormant C. neoformans. The experimental use of fluorescent mutants may shed light on C. neoformans-host interactions and fungal biology, including dormant phenotypes.
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Affiliation(s)
- Raffael Júnio Araújo de Castro
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
| | - Marco Túlio Aidar Mariano Rêgo
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Fabiana S. Brandão
- Faculty of Health Science, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Ana Laura Alfonso Pérez
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Janice Lisboa De Marco
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Marcio José Poças-Fonseca
- Department of Genetics and Morphology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Connie Nichols
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - J. Andrew Alspaugh
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - Maria Sueli S. Felipe
- Catholic University of Brasilia, Campus Asa Norte, Asa Norte, Brasília, Federal District, Brazil
| | - Alexandre Alanio
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
- Laboratoire de Mycologie et Parasitologie, AP-HP, Hôpital Saint Louis, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Anamélia Lorenzetti Bocca
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Larissa Fernandes
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- Faculty of Ceilândia, Campus UnB Ceilândia, University of Brasília, Ceilândia Sul, Brasília, Federal District, Brazil
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21
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Denham ST, Brammer B, Chung KY, Wambaugh MA, Bednarek JM, Guo L, Moreau CT, Brown JCS. A dissemination-prone morphotype enhances extrapulmonary organ entry by Cryptococcus neoformans. Cell Host Microbe 2022; 30:1382-1400.e8. [PMID: 36099922 PMCID: PMC9588642 DOI: 10.1016/j.chom.2022.08.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/01/2022] [Accepted: 08/18/2022] [Indexed: 01/08/2023]
Abstract
Environmental pathogens move from ecological niches to mammalian hosts, requiring adaptation to dramatically different environments. Microbes that disseminate farther, including the fungal meningitis pathogen Cryptococcus neoformans, require additional adaptation to diverse tissues. We demonstrate that the formation of a small C. neoformans morphotype-called "seed" cells due to their colonizing ability-is critical for extrapulmonary organ entry. Seed cells exhibit changes in fungal cell size and surface expression that result in an enhanced macrophage update. Seed cell formation is triggered by environmental factors, including C. neoformans' environmental niche, and pigeon guano with phosphate plays a central role. Seed cells show the enhanced expression of phosphate acquisition genes, and mutants unable to acquire phosphate fail to adopt the seed cell morphotype. Additionally, phosphate can be released by tissue damage, potentially establishing a feed-forward loop of seed cell formation and dissemination. Thus, C. neoformans' size variation represent inducible morphotypes that change host interactions to facilitate microbe spread.
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Affiliation(s)
- Steven T Denham
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Brianna Brammer
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Krystal Y Chung
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Morgan A Wambaugh
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Joseph M Bednarek
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Li Guo
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Christian T Moreau
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Jessica C S Brown
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA.
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22
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Abstract
Neurocritical care (NCC) is an emerging field within critical care medicine, reflecting the widespread prevalence of neurologic injury in critically ill patients. Morbidity and mortality from neurocritical illness (NCI) have been reduced substantially in resource-rich settings (RRS), owing to the development of advanced technologies, neuro-specific units, and subspecialized medical training. Despite shouldering much of the burden of NCI worldwide, resource-limited settings (RLS) face immense hurdles when implementing guidelines generated in RRS. This review summarizes the current epidemiology, management, and outcomes of the most common NCIs in RLS and offers commentary on future directions in NCC practiced in RLS.
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23
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Cross-Kingdom Infection of Macrophages Reveals Pathogen- and Immune-Specific Global Reprogramming and Adaptation. mBio 2022; 13:e0168722. [PMID: 35862772 PMCID: PMC9426421 DOI: 10.1128/mbio.01687-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relationship between the human microbiota and infectious disease outcome is a rapidly expanding area of study. Understanding how the host responds to changes in its symbiotic relationship with microbes provides new insight into how disruption can promote disease.
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24
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An Immunogenic and Slow-Growing Cryptococcal Strain Induces a Chronic Granulomatous Infection in Murine Lungs. Infect Immun 2022; 90:e0058021. [PMID: 35587201 PMCID: PMC9202370 DOI: 10.1128/iai.00580-21] [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] [Indexed: 11/20/2022] Open
Abstract
Many successful pathogens cause latent infections, remaining dormant within the host for years but retaining the ability to reactivate to cause symptomatic disease. The human opportunistic fungal pathogen Cryptococcus neoformans establishes latent pulmonary infections in immunocompetent individuals upon inhalation from the environment. These latent infections are frequently characterized by granulomas, or foci of chronic inflammation, that contain dormant and persistent cryptococcal cells. Immunosuppression can cause these granulomas to break down and release fungal cells that proliferate, disseminate, and eventually cause lethal cryptococcosis. This course of fungal latency and reactivation is understudied due to limited models, as chronic pulmonary granulomas do not typically form in mouse cryptococcal infections. A loss-of-function mutation in the Cryptococcus-specific MAR1 gene was previously described to alter cell surface remodeling in response to host signals. Here, we demonstrate that the mar1Δ mutant strain persists long term in a murine inhalation model of cryptococcosis, inducing a chronic pulmonary granulomatous response. We find that murine infections with the mar1Δ mutant strain are characterized by reduced fungal burden, likely due to the low growth rate of the mar1Δ mutant strain at physiological temperature, and an altered host immune response, likely due to inability of the mar1Δ mutant strain to properly employ virulence factors. We propose that this combination of features in the mar1Δ mutant strain collectively promotes the induction of a more chronic inflammatory response and enables long-term fungal persistence within these granulomatous regions.
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25
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Cryptococcus spp. and Cryptococcosis: focusing on the infection in Brazil. Braz J Microbiol 2022; 53:1321-1337. [PMID: 35486354 PMCID: PMC9433474 DOI: 10.1007/s42770-022-00744-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 03/25/2022] [Indexed: 11/02/2022] Open
Abstract
Cryptococcosis is a global fungal infection caused by the Cryptococcus neoformans/Cryptococcus gattii yeast complex. This infection is acquired by inhalation of propagules such as basidiospores or dry yeast, initially causing lung infections with the possibility of progressing to the meninges. This infection mainly affects immunocompromised HIV and transplant patients; however, immunocompetent patients can also be affected. This review proposes to evaluate cryptococcosis focusing on studies of this mycosis in Brazilian territory; moreover, recent advances in the understanding of its virulence mechanism, animal models in research are also assessed. For this, literature review as realized in PubMed, Scielo, and Brazilian legislation. In Brazil, cryptococcosis has been identified as one of the most lethal fungal infections among HIV patients and C. neoformans VNI and C. gattii VGII are the most prevalent genotypes. Moreover, different clinical settings published in Brazil were described. As in other countries, cryptococcosis is difficult to treat due to a limited therapeutic arsenal, which is highly toxic and costly. The presence of a polysaccharide capsule, thermo-tolerance, production of melanin, biofilm formation, mechanisms for iron use, and morphological alterations is an important virulence mechanism of these yeasts. The introduction of cryptococcosis as a compulsory notification disease could improve data regarding incidence and help in the management of these infections.
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26
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Joseph SK, M A A, Thomas S, Nair SC. Nanomedicine as a future therapeutic approach for treating meningitis. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2021.102968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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27
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Black B, Lee C, Horianopoulos LC, Jung WH, Kronstad JW. Respiring to infect: Emerging links between mitochondria, the electron transport chain, and fungal pathogenesis. PLoS Pathog 2021; 17:e1009661. [PMID: 34237096 PMCID: PMC8266039 DOI: 10.1371/journal.ppat.1009661] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Braydon Black
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Christopher Lee
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Linda C. Horianopoulos
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, Republic of Korea
| | - James W. Kronstad
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
- * E-mail:
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28
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The interplay of phenotype and genotype in Cryptococcus neoformans disease. Biosci Rep 2021; 40:226594. [PMID: 33021310 PMCID: PMC7569153 DOI: 10.1042/bsr20190337] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/23/2020] [Accepted: 10/06/2020] [Indexed: 12/17/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening meningitis primarily in immunocompromised individuals. In order to survive and proliferate during infection, C. neoformans must adapt to a variety of stresses it encounters within the host. Patient outcome depends on the interaction between the pathogen and the host. Understanding the mechanisms that C. neoformans uses to facilitate adaptation to the host and promote pathogenesis is necessary to better predict disease severity and establish proper treatment. Several virulence phenotypes have been characterized in C. neoformans, but the field still lacks a complete understanding of how genotype and phenotype contribute to clinical outcome. Furthermore, while it is known that C. neoformans genotype impacts patient outcome, the mechanisms remain unknown. This lack of understanding may be due to the genetic heterogeneity of C. neoformans and the extensive phenotypic variation observed between and within isolates during infection. In this review, we summarize the current understanding of how the various genotypes and phenotypes observed in C. neoformans correlate with human disease progression in the context of patient outcome and recurrence. We also postulate the mechanisms underlying the genetic and phenotypic changes that occur in vivo to promote rapid adaptation in the host.
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29
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Kalem MC, Humby MS, Wohlfert EA, Jacobs A, Panepinto JC. Cryptococcus neoformans Coinfection Dampens the TNF-α Response in HIV-1-Infected Human THP-1 Macrophages. mSphere 2021; 6:e00213-21. [PMID: 33762317 PMCID: PMC8546698 DOI: 10.1128/msphere.00213-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/08/2021] [Indexed: 01/14/2023] Open
Abstract
Cryptococcus neoformans is a devastating opportunistic fungal pathogen. It mostly impacts people in an immunocompromised state, such as people living with HIV/AIDS and following organ transplantation. Macrophages, in addition to being a major cellular reservoir of HIV-1, represent a unique niche in which both C. neoformans and HIV-1 can coinhabit in the course of natural infection. Here, we report the observation that HIV-1 infection of THP-1 macrophages increases the rate at which they phagocytose C. neoformans cells. We investigated the tumor necrosis factor alpha (TNF-α) signaling and nuclear factor kappa B (NF-κB) activation in human monocyte-derived macrophages infected with HIV-1 alone, as well as those coinfected with HIV-1 and C. neoformans Our findings showed that while HIV-1 infection alone upregulates TNF-α production and activates NF-κB signaling, C. neoformans coinfection drastically and rapidly dampens this proinflammatory response. These data suggest an antagonism between two important human pathogens during coinfection of macrophages.IMPORTANCE Fungal infections are one of the leading causes of death for people who live with HIV/AIDS. Even though these pathogens are independently well studied, it is still enigmatic how coinfection with HIV-1 and C. neoformans alters gene expression and cellular processes, especially in clinically relevant cell types. Understanding the interplay between these two pathogens is especially critical because C. neoformans mortality largely depends on the host's immunocompromised state during viral infection. Studying this coinfection is challenging since HIV-1 only infects human cells, and the modified murine HIV-1 virus does not reproduce the clinical landmarks of HIV-1 infection or AIDS in mice. Our observations shed light on how these two pathogens trigger opposing trends in TNF-α and NF-κB signaling in human monocyte-derived macrophages.
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Affiliation(s)
- Murat C Kalem
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, New York, USA
| | - Monica S Humby
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, New York, USA
| | - Elizabeth A Wohlfert
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, New York, USA
| | - Amy Jacobs
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, New York, USA
| | - John C Panepinto
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, New York, USA
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30
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Abstract
Although we have recognized cryptococcosis as a disease entity for well over 100 years, there are many details about its pathogenesis which remain unknown. A major barrier to better understanding is the very broad range of clinical and pathological forms cryptococcal infections can take. One such form has been historically called the cryptococcal granuloma, or the cryptococcoma. These words have been used to describe essentially any mass lesion associated with infection, due to their presumed similarity to the quintessential granuloma, the tubercle in tuberculosis. Although clear distinctions between tuberculosis and cryptococcal disease have been discovered, cellular and molecular studies still confirm some important parallels between these 2 diseases and what we now call granulomatous inflammation. In this review, we shall sketch out some of the history behind the term "granuloma" as it pertains to cryptococcal disease, explore our current understanding of the biology of granuloma formation, and try to place that understanding in the context of the myriad pathological presentations of this infection. Finally, we shall summarize the role of the granuloma in cryptococcal latency and present opportunities for future investigations.
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Affiliation(s)
- Laura C. Ristow
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - J. Muse Davis
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
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31
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Alanio A. Dormancy in Cryptococcus neoformans: 60 years of accumulating evidence. J Clin Invest 2021; 130:3353-3360. [PMID: 32484459 DOI: 10.1172/jci136223] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic yeast that is present worldwide and interacts with various organisms. In humans, it is responsible for cryptococcosis, a deadly invasive fungal infection that represents around 220,000 cases per year worldwide. Starting from the natural history of the disease in humans, there is accumulating evidence on the capacity of this organism to enter dormancy. In response to the harsh host environment, the yeast is able to adapt dramatically and escape the vigilance of the host's immune cells to survive. Indeed, the yeast exposed to the host takes on pleiotropic phenotypes, enabling the generation of populations in heterogeneous states, including dormancy, to eventually survive at low metabolic cost and revive in favorable conditions. The concept of dormancy has been validated in C. neoformans from both epidemiological and genotyping data, and more recently from the biological point of view with the characterization of dormancy through the description of viable but nonculturable cells.
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Affiliation(s)
- Alexandre Alanio
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.,Molecular Mycology Unit, CNRS UMR 2000, National Reference Center for Invasive Mycoses and Antifungals (NRCMA), Institut Pasteur, Paris, France.,Université de Paris, Paris, France
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32
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Wijburg MT, Warnke C, McGuigan C, Koralnik IJ, Barkhof F, Killestein J, Wattjes MP. Pharmacovigilance during treatment of multiple sclerosis: early recognition of CNS complications. J Neurol Neurosurg Psychiatry 2021; 92:177-188. [PMID: 33229453 DOI: 10.1136/jnnp-2020-324534] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/27/2020] [Accepted: 10/05/2020] [Indexed: 12/22/2022]
Abstract
An increasing number of highly effective disease-modifying therapies for people with multiple sclerosis (MS) have recently gained marketing approval. While the beneficial effects of these drugs in terms of clinical and imaging outcome measures is welcomed, these therapeutics are associated with substance-specific or group-specific adverse events that include severe and fatal complications. These adverse events comprise both infectious and non-infectious complications that can occur within, or outside of the central nervous system (CNS). Awareness and risk assessment strategies thus require interdisciplinary management, and robust clinical and paraclinical surveillance strategies. In this review, we discuss the current role of MRI in safety monitoring during pharmacovigilance of patients treated with (selective) immune suppressive therapies for MS. MRI, particularly brain MRI, has a pivotal role in the early diagnosis of CNS complications that potentially are severely debilitating and may even be lethal. Early recognition of such CNS complications may improve functional outcome and survival, and thus knowledge on MRI features of treatment-associated complications is of paramount importance to MS clinicians, but also of relevance to general neurologists and radiologists.
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Affiliation(s)
- Martijn T Wijburg
- Department of Neurology, MS Center Amsterdam, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands .,Department of Radiology & Nuclear Medicine, MS Center Amsterdam, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Clemens Warnke
- Department of Neurology, University Hospital Köln, University of Cologne, Köln, Germany.,Department of Neurology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany
| | - Christopher McGuigan
- Department of Neurology, St Vincent's University Hospital & University College Dublin, Dublin, Ireland
| | - Igor J Koralnik
- Department of Neurological Sciences, Division of Neuroinfectious Diseases, Rush University Medical Center, Chicago, Illinois, USA
| | - Frederik Barkhof
- Department of Radiology & Nuclear Medicine, MS Center Amsterdam, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands.,Institutes of Neurology and Healthcare Engineering, UCL, London, UK
| | - Joep Killestein
- Department of Neurology, MS Center Amsterdam, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Mike P Wattjes
- Department of Radiology & Nuclear Medicine, MS Center Amsterdam, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands.,Department of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
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33
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Yu CH, Chen Y, Desjardins CA, Tenor JL, Toffaletti DL, Giamberardino C, Litvintseva A, Perfect JR, Cuomo CA. Landscape of gene expression variation of natural isolates of Cryptococcus neoformans in response to biologically relevant stresses. Microb Genom 2020; 6. [PMID: 31860441 PMCID: PMC7067042 DOI: 10.1099/mgen.0.000319] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that at its peak epidemic levels caused an estimated million cases of cryptococcal meningitis per year worldwide. This species can grow in diverse environmental (trees, soil and bird excreta) and host niches (intracellular microenvironments of phagocytes and free-living in host tissues). The genetic basic for adaptation to these different conditions is not well characterized, as most experimental work has relied on a single reference strain of C. neoformans. To identify genes important for yeast infection and disease progression, we profiled the gene expression of seven C. neoformans isolates grown in five representative in vitro environmental and in vivo conditions. We characterized gene expression differences using RNA-Seq (RNA sequencing), comparing clinical and environmental isolates from two of the major lineages of this species, VNI and VNBI. These comparisons highlighted genes showing lineage-specific expression that are enriched in subtelomeric regions and in lineage-specific gene clusters. By contrast, we find few expression differences between clinical and environmental isolates from the same lineage. Gene expression specific to in vivo stages reflects available nutrients and stresses, with an increase in fungal metabolism within macrophages, and an induction of ribosomal and heat-shock gene expression within the subarachnoid space. This study provides the widest view to date of the transcriptome variation of C. neoformans across natural isolates, and provides insights into genes important for in vitro and in vivo growth stages.
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Affiliation(s)
- Chen-Hsin Yu
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yuan Chen
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Dena L Toffaletti
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Charles Giamberardino
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Anastasia Litvintseva
- Mycotic Diseases Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
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34
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Normile TG, Bryan AM, Del Poeta M. Animal Models of Cryptococcus neoformans in Identifying Immune Parameters Associated With Primary Infection and Reactivation of Latent Infection. Front Immunol 2020; 11:581750. [PMID: 33042164 PMCID: PMC7522366 DOI: 10.3389/fimmu.2020.581750] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
Cryptococcus species are environmental fungal pathogens and the causative agents of cryptococcosis. Infection occurs upon inhalation of infectious particles, which proliferate in the lung causing a primary infection. From this primary lung infection, fungal cells can eventually disseminate to other organs, particularly the brain, causing lethal meningoencephalitis. However, in most cases, the primary infection resolves with the formation of a lung granuloma. Upon severe immunodeficiency, dormant cryptococcal cells will start proliferating in the lung granuloma and eventually will disseminate to the brain. Many investigators have sought to study the protective host immune response to this pathogen in search of host parameters that keep the proliferation of cryptococcal cells under control. The majority of the work assimilates research carried out using the primary infection animal model, mainly because a reactivation model has been available only very recently. This review will focus on anti-cryptococcal immunity in both the primary and reactivation models. An understanding of the differences in host immunity between the primary and reactivation models will help to define the key host parameters that control the infections and are important for the research and development of new therapeutic and vaccine strategies against cryptococcosis.
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Affiliation(s)
- Tyler G Normile
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States
| | - Arielle M Bryan
- Ingenious Targeting Laboratory Incorporated, Ronkonkoma, NY, United States
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States.,Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY, United States.,Veterans Administration Medical Center, Northport, NY, United States
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35
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Molecular Epidemiology Reveals Low Genetic Diversity among Cryptococcus neoformans Isolates from People Living with HIV in Lima, Peru, during the Pre-HAART Era. Pathogens 2020; 9:pathogens9080665. [PMID: 32824653 PMCID: PMC7459599 DOI: 10.3390/pathogens9080665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/14/2020] [Accepted: 08/15/2020] [Indexed: 02/07/2023] Open
Abstract
Cryptococcosis, a mycosis presenting mostly as meningoencephalitis, affecting predominantly human immunodeficiency virus (HIV)-infected people, is mainly caused by Cryptococcus neoformans. The genetic variation of 48 C. neoformans isolates, recovered from 20 HIV-positive people in Lima, Peru, during the pre-highly active antiretroviral therapy (HAART) era, was studied retrospectively. The mating type of the isolates was determined by PCR, and the serotype by agglutination and CAP59-restriction fragment length polymorphism (RFLP). Genetic diversity was assessed by URA5-RFLP, PCR-fingerprinting, amplified fragment length polymorphism (AFLP), and multilocus sequence typing (MLST). All isolates were mating type alpha, with 39 molecular type VNI, seven VNII, corresponding to C. neoformans var. grubii serotype A, and two VNIII AD hybrids. Overall, the cryptococcal population from HIV-positive people in Lima shows a low degree of genetic diversity. In most patients with persistent cryptococcal infection, the same genotype was recovered during the follow-up. In four patients with relapse and one with therapy failure, different genotypes were found in isolates from the re-infection and from the isolate recovered at the end of the treatment. In one patient, two genotypes were found in the first cryptococcosis episode. This study contributes data from Peru to the ongoing worldwide population genetic analysis of Cryptococcus.
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36
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Yang M, Cheng L, Sun F, Liu F, Feng W, Yao P, Weng B, Xia P. Comparison of cryptococcal meningitis in HIV-negative patients with and without lung infections. J Int Med Res 2020; 48:300060520929591. [PMID: 32527201 PMCID: PMC7294499 DOI: 10.1177/0300060520929591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Objective To investigate the clinical features and outcomes of cryptococcal meningitis (CM) in HIV-negative patients with and without lung infections. Methods We retrospectively reviewed the medical records of HIV-negative patients with CM admitted to two university hospitals in Southwest China over the past 5 years. Results Seventy-one patients were included, of whom 35 (49.3%) had lung disease. Compared with patients without lung infection, CM patients with lung infection tended to be male and younger (≤30 years), experienced more fever, less vomiting and fewer central nervous system symptoms; more often had low white blood cell (WBC) counts (<20 × 106/L), and fewer often had ethmoid sinusitis, maxillary sinusitis, paranasal sinusitis, and otitis media. Cryptococcus neoformans isolates from these patients were sensitive to itraconazole, voriconazole, fluconazole, and amphotericin B but resistant to flucytosine. CM patients with lung infection had higher mortality at discharge compared with patients without lung infection (8.6% vs. 0%). Multivariable analyses showed that a WBC count <20 × 106/L was significantly associated with poor treatment outcome (odds ratio 0.01, 95% confidence interval 0–0.83). Conclusion HIV-negative CM patients with lung infections tended to be male and younger. Fever, fewer central nervous system symptoms, and WBC counts <20 × 106/L were characteristic of this patient group.
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Affiliation(s)
- Ming Yang
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China.,Department of Pharmacy, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Lin Cheng
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China
| | - Fengjun Sun
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China
| | - Fu Liu
- Department of Pharmacy, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Wei Feng
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China
| | - Pu Yao
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China
| | - Bangbi Weng
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China
| | - Peiyuan Xia
- Department of Pharmacy, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China
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Abstract
Advances in medicine have resulted in the discovery and implementation of treatments for human disease. While these recent advances have been beneficial, procedures such as solid-organ transplants and cancer treatments have left many patients in an immunocompromised state. Furthermore, the emergence of immunocompromising diseases such as HIV/AIDS or other immunosuppressive medical conditions have opened an opportunity for fungal infections to afflict patients globally. The development of drug resistance in human-pathogenic fungi and the limited array of antifungal drugs has left us in a scenario where we need to develop new therapeutic approaches to treat fungal infections that are less prone to the development of resistance by pathogenic fungi. The significance of our work lies in utilizing a novel nanoemulsion formulation to treat topical fungal infections while minimizing risks of drug resistance development. Infections triggered by pathogenic fungi cause a serious threat to the public health care system. In particular, an increase of antifungal drug-resistant fungi has resulted in difficulty in treatment. A limited variety of antifungal drugs available to treat patients has left us in a situation where we need to develop new therapeutic approaches that are less prone to development of resistance by pathogenic fungi. In this study, we demonstrate the efficacy of the nanoemulsion NB-201, which utilizes the surfactant benzalkonium chloride, against human-pathogenic fungi. We found that NB-201 exhibited in vitro activity against Candidaalbicans, including both planktonic growth and biofilms. Furthermore, treatments with NB-201 significantly reduced the fungal burden at the infection site and presented an enhanced healing process after subcutaneous infections by multidrug-resistant C. albicans in a murine host system. NB-201 also exhibited in vitro growth inhibition activity against other fungal pathogens, including Cryptococcus spp., Aspergillus fumigatus, and Mucorales. Due to the nature of the activity of this nanoemulsion, there is a minimized chance of drug resistance developing, presenting a novel treatment to control fungal wound or skin infections. IMPORTANCE Advances in medicine have resulted in the discovery and implementation of treatments for human disease. While these recent advances have been beneficial, procedures such as solid-organ transplants and cancer treatments have left many patients in an immunocompromised state. Furthermore, the emergence of immunocompromising diseases such as HIV/AIDS or other immunosuppressive medical conditions have opened an opportunity for fungal infections to afflict patients globally. The development of drug resistance in human-pathogenic fungi and the limited array of antifungal drugs has left us in a scenario where we need to develop new therapeutic approaches to treat fungal infections that are less prone to the development of resistance by pathogenic fungi. The significance of our work lies in utilizing a novel nanoemulsion formulation to treat topical fungal infections while minimizing risks of drug resistance development.
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Zafar H, Altamirano S, Ballou ER, Nielsen K. A titanic drug resistance threat in Cryptococcus neoformans. Curr Opin Microbiol 2019; 52:158-164. [PMID: 31765991 DOI: 10.1016/j.mib.2019.11.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/01/2019] [Accepted: 11/01/2019] [Indexed: 10/25/2022]
Abstract
Increasing resistance to frontline antifungals is a growing threat to global health. In the face of high rates of relapse for patients with cryptococcal meningitis and frequent drug resistance in clinical isolates, recent insights into Cryptococcus neoformans morphogenesis and genome plasticity take on new and urgent meaning. Here we review the state of the understanding of mechanisms of drug resistance in the context of host-relevant changes in Cryptococcus morphology and cell ploidy.
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Affiliation(s)
- Hanna Zafar
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Sophie Altamirano
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455 USA
| | - Elizabeth R Ballou
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455 USA.
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Kassi FK, Drakulovski P, Bellet V, Roger F, Chabrol A, Krasteva D, Doumbia A, Landman R, Kakou A, Reynes J, Delaporte E, Menan HEI, Bertout S. Cryptococcus genetic diversity and mixed infections in Ivorian HIV patients: A follow up study. PLoS Negl Trop Dis 2019; 13:e0007812. [PMID: 31738768 PMCID: PMC6886875 DOI: 10.1371/journal.pntd.0007812] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 12/02/2019] [Accepted: 09/26/2019] [Indexed: 01/07/2023] Open
Abstract
Genetic diversity analyses were performed by sero-genotyping and multi-locus sequence typing on 252 cryptococcal isolates from 13 HIV-positive Ivorian patients followed-up for cryptococcal meningitis. Antifungal susceptibility analyses were performed according to the CLSI M27A3 method. The majority (67.8%) of the isolates belonged to the Cryptococcus neoformans (serotype A) species complex, with 93% being VNI and 7% being VNII. Cryptococcus deuterogattii VGII (serotype B) represented 16.7% of the strains, while C. neoformans/C. deneoformans VNIII (serotype AD) hybrids accounted for 15.1% of the strains. One strain (0.4%) was not identifiable. Nine different sequence types (STs 5, 6, 23, 40, 93, 207, 311, and a new ST; 555) were identified in the C. neoformans population, while the C. deuterogattii population comprised the single ST 173. The distribution of the strains showed that, while the majority of patients (9/13) harboured a single sequence type, 4 patients showed mixed infections. These patients experienced up to 4 shifts in strain content either at the species and/or ST level during their follow-up. This evolution of diversity over time led to the co-existence of up to 3 different Cryptococcus species and 4 different ST within the same individual during the course of infection. Susceptibility testing showed that all strains were susceptible to amphotericin B while 3.6% of them had a none-wild type phenotype to 5-flucytosine. Concerning fluconazole, 2.9% of C.neoformans serotype A strains and 2.4% of C. deuterogattii had also respectively a none-wild type phenotype to this molecule. All C. neoformans x C. deneoformans serotype AD hybrids had however a wild type phenotype to fluconazole. The present study showed that mixed infections exist and could be of particular importance for care outcomes. Indeed, (i) the different Cryptococcus species are known to exhibit different virulence and different susceptibility patterns to antifungal drugs and (ii) the strains genetic diversity within the samples may influence the susceptibility to antifungal treatment.
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Affiliation(s)
- Fulgence Kondo Kassi
- Université Félix Houphouet-Boigny, Unité des Sciences Pharmaceutiques et Biologiques, Abidjan, Côte d’Ivoire
| | - Pascal Drakulovski
- Laboratoire de Parasitologie et Mycologie Médicale, IRD UMI 233, INSERM U1175, Université de Montpellier, Unité TransVIHMI, Montpellier, France
| | - Virginie Bellet
- Laboratoire de Parasitologie et Mycologie Médicale, IRD UMI 233, INSERM U1175, Université de Montpellier, Unité TransVIHMI, Montpellier, France
| | - Frédéric Roger
- Laboratoire de Parasitologie et Mycologie Médicale, IRD UMI 233, INSERM U1175, Université de Montpellier, Unité TransVIHMI, Montpellier, France
| | - Amélie Chabrol
- Service de Maladies Infectieuses et Tropicales, CH Sud Francilien, Corbeil, France
| | - Donika Krasteva
- Laboratoire de Parasitologie et Mycologie Médicale, IRD UMI 233, INSERM U1175, Université de Montpellier, Unité TransVIHMI, Montpellier, France
| | - Adama Doumbia
- Université Félix Houphouet-Boigny, Unité des Sciences Pharmaceutiques et Biologiques, Abidjan, Côte d’Ivoire
| | - Roland Landman
- Institut de Médecine et Epidémiologie Appliquée (IMEA), Fondation Léon M’Ba, Paris, France
| | - Aka Kakou
- Service des Maladies Infectieuses et Tropicales, CHU Treichville, Abidjan, Côte d’Ivoire
| | - Jacques Reynes
- CHU Gui de Chauliac, Service des Maladies Infectieuses et Tropicales, IRD UMI 233, INSERM U1175, Université de Montpellier, Unité TransVIHMI, Montpellier, France
| | - Eric Delaporte
- TransVIHMI/INSERM1175, Institut de Recherche pour le Développement (IRD) and University of Montpellier, Montpellier, France
| | - Hervé Eby Ignace Menan
- Diagnostic and Research Center on AIDS and Other Infectious Diseases (CeDReS), Abidjan, Côte d'Ivoire
| | - Sébastien Bertout
- Laboratoire de Parasitologie et Mycologie Médicale, IRD UMI 233, INSERM U1175, Université de Montpellier, Unité TransVIHMI, Montpellier, France
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Abstract
PURPOSE OF REVIEW Defective cell-mediated immunity is a major risk factor for cryptococcosis, a fatal disease if untreated. Cryptococcal meningitis (CM), the main presentation of disseminated disease, occurs through hematogenous spread to the brain from primary pulmonary foci, facilitated by yeast virulence factors. We revisit remarkable recent improvements in the prevention, diagnosis and management of CM. RECENT FINDINGS Cryptococcal antigen (CrAg), main capsular polysaccharide of Cryptococcus spp. is detectable in blood and cerebrospinal fluid of infected patients with point of care lateral flow assays. Recent World Health Organization guidelines recommend 7-day amphotericin B plus flucytosine, then 7-day high dose (1200 mg/day) fluconazole for induction treatment of HIV-associated CM. Management of raised intracranial pressure, a consequence of CM, should rely mainly on daily therapeutic lumbar punctures until normalisation. In HIV-associated CM, following introduction of antifungal therapy, (re)initiation of antiretroviral therapy should be delayed by 4-6 weeks to prevent immune reconstitution inflammatory syndrome, common in CM. CM is a fatal disease whose diagnosis has recently been simplified. Treatment should always include antifungal combination therapy and management of raised intracranial pressure. Screening for immune deficiency should be mandatory in all patients with cryptococcosis.
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Leipheimer J, Bloom ALM, Panepinto JC. Protein Kinases at the Intersection of Translation and Virulence. Front Cell Infect Microbiol 2019; 9:318. [PMID: 31572689 PMCID: PMC6749009 DOI: 10.3389/fcimb.2019.00318] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/26/2019] [Indexed: 12/14/2022] Open
Abstract
As free living organisms, fungi are challenged with a variety of environmental insults that threaten their cellular processes. In some cases, these challenges mimic conditions present within mammals, resulting in the accidental selection of virulence factors over evolutionary time. Be it within a host or the soil, fungi must contend with environmental challenges through the production of stress effector proteins while maintaining factors required for viability in any condition. Initiation and upkeep of this balancing act is mainly under the control of kinases that affect the propensity and selectivity of protein translation. This review will focus on kinases in pathogenic fungi that facilitate a virulence phenotype through translational control.
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Affiliation(s)
- Jay Leipheimer
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Amanda L M Bloom
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - John C Panepinto
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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Abstract
Cryptococcus neoformans is a ubiquitous environmental fungus and an opportunistic pathogen that causes fatal cryptococcal meningitis. Advances in genomics, genetics, and cellular and molecular biology of C. neoformans have dramatically improved our understanding of this important pathogen, rendering it a model organism to study eukaryotic biology and microbial pathogenesis. In light of recent progress, we describe in this review the life cycle of C. neoformans with a special emphasis on the regulation of the yeast-to-hypha transition and different modes of sexual reproduction, in addition to the impacts of the life cycle on cryptococcal populations and pathogenesis.
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Affiliation(s)
- Youbao Zhao
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
| | - Jianfeng Lin
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
| | - Yumeng Fan
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
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Hommel B, Sturny-Leclère A, Volant S, Veluppillai N, Duchateau M, Yu CH, Hourdel V, Varet H, Matondo M, Perfect JR, Casadevall A, Dromer F, Alanio A. Cryptococcus neoformans resists to drastic conditions by switching to viable but non-culturable cell phenotype. PLoS Pathog 2019; 15:e1007945. [PMID: 31356623 PMCID: PMC6687208 DOI: 10.1371/journal.ppat.1007945] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/08/2019] [Accepted: 06/27/2019] [Indexed: 01/22/2023] Open
Abstract
Metabolically quiescent pathogens can persist in a viable non-replicating state for months or even years. For certain infectious diseases, such as tuberculosis, cryptococcosis, histoplasmosis, latent infection is a corollary of this dormant state, which has the risk for reactivation and clinical disease. During murine cryptococcosis and macrophage uptake, stress and host immunity induce Cryptococcus neoformans heterogeneity with the generation of a sub-population of yeasts that manifests a phenotype compatible with dormancy (low stress response, latency of growth). In this subpopulation, mitochondrial transcriptional activity is regulated and this phenotype has been considered as a hallmark of quiescence in stem cells. Based on these findings, we worked to reproduce this phenotype in vitro and then standardize the experimental conditions to consistently generate this dormancy in C. neoformans. We found that incubation of stationary phase yeasts (STAT) in nutriment limited conditions and hypoxia for 8 days (8D-HYPOx) was able to produced cells that mimic the phenotype obtained in vivo. In these conditions, mortality and/or apoptosis occurred in less than 5% of the yeasts compared to 30-40% of apoptotic or dead yeasts upon incubation in normoxia (8D-NORMOx). Yeasts in 8D-HYPOx harbored a lower stress response, delayed growth and less that 1% of culturability on agar plates, suggesting that these yeasts are viable but non culturable cells (VBNC). These VBNC were able to reactivate in the presence of pantothenic acid, a vitamin that is known to be involved in quorum sensing and a precursor of acetyl-CoA. Global metabolism of 8D-HYPOx cells showed some specific requirements and was globally shut down compared to 8D-NORMOx and STAT conditions. Mitochondrial analyses showed that the mitochondrial mass increased with mitochondria mostly depolarized in 8D-HYPOx compared to 8D-NORMox, with increased expression of mitochondrial genes. Proteomic and transcriptomic analyses of 8D-HYPOx revealed that the number of secreted proteins and transcripts detected also decreased compared to 8D-NORMOx and STAT, and the proteome, secretome and transcriptome harbored specific profiles that are engaged as soon as four days of incubation. Importantly, acetyl-CoA and the fatty acid pathway involving mitochondria are required for the generation and viability maintenance of VBNC. Altogether, these data show that we were able to generate for the first time VBNC phenotype in C. neoformans. This VBNC state is associated with a specific metabolism that should be further studied to understand dormancy/quiescence in this yeast.
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Affiliation(s)
- Benjamin Hommel
- Institut Pasteur, CNRS, Molecular Mycology Unit, UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | - Stevenn Volant
- Institut Pasteur - Bioinformatics and Biostatistics Hub - C3BI, USR 3756 IP CNRS, Paris, France
| | | | - Magalie Duchateau
- Institut Pasteur, Unité de spectrométrie de masse et Protéomique, Paris, France
| | - Chen-Hsin Yu
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Véronique Hourdel
- Institut Pasteur, Unité de spectrométrie de masse et Protéomique, Paris, France
| | - Hugo Varet
- Institut Pasteur - Bioinformatics and Biostatistics Hub - C3BI, USR 3756 IP CNRS, Paris, France
- Institut Pasteur - Transcriptome and Epigenome Platform - Biomics Pole - C2RT, Paris, France
| | - Mariette Matondo
- Institut Pasteur, Unité de spectrométrie de masse et Protéomique, Paris, France
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Françoise Dromer
- Institut Pasteur, CNRS, Molecular Mycology Unit, UMR2000, Paris, France
| | - Alexandre Alanio
- Institut Pasteur, CNRS, Molecular Mycology Unit, UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
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Denham ST, Wambaugh MA, Brown JCS. How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts. J Mol Biol 2019; 431:2982-3009. [PMID: 31078554 PMCID: PMC6646061 DOI: 10.1016/j.jmb.2019.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/18/2019] [Accepted: 05/01/2019] [Indexed: 12/11/2022]
Abstract
Environmental fungi are globally ubiquitous and human exposure is near universal. However, relatively few fungal species are capable of infecting humans, and among fungi, few exposure events lead to severe systemic infections. Systemic infections have mortality rates of up to 90%, cost the US healthcare system $7.2 billion annually, and are typically associated with immunocompromised patients. Despite this reputation, exposure to environmental fungi results in a range of outcomes, from asymptomatic latent infections to severe systemic infection. Here we discuss different exposure outcomes for five major fungal pathogens: Aspergillus, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma species. These fungi include a mold, a budding yeast, and thermal dimorphic fungi. All of these species must adapt to dramatically changing environments over the course of disease. These dynamic environments include the human lung, which is the first exposure site for these organisms. Fungi must defend themselves against host immune cells while germinating and growing, which risks further exposing microbe-associated molecular patterns to the host. We discuss immune evasion strategies during early infection, from disruption of host immune cells to major changes in fungal cell morphology.
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Affiliation(s)
- Steven T Denham
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Morgan A Wambaugh
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Jessica C S Brown
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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Fillinger RJ, Anderson MZ. Seasons of change: Mechanisms of genome evolution in human fungal pathogens. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2019; 70:165-174. [PMID: 30826447 DOI: 10.1016/j.meegid.2019.02.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/23/2019] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Fungi are a diverse kingdom of organisms capable of thriving in various niches across the world including those in close association with multicellular eukaryotes. Fungal pathogens that contribute to human disease reside both within the host as commensal organisms of the microbiota and the environment. Their niche of origin dictates how infection initiates but also places specific selective pressures on the fungal pathogen that contributes to its genome organization and genetic repertoire. Recent efforts to catalogue genomic variation among major human fungal pathogens have unveiled evolutionary themes that shape the fungal genome. Mechanisms ranging from large scale changes such as aneuploidy and ploidy cycling as well as more targeted mutations like base substitutions and gene copy number variations contribute to the evolution of these species, which are often under multiple competing selective pressures with their host, environment, and other microbes. Here, we provide an overview of the major selective pressures and mechanisms acting to evolve the genome of clinically important fungal pathogens of humans.
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Affiliation(s)
- Robert J Fillinger
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA
| | - Matthew Z Anderson
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA; Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
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de Oliveira HC, Trevijano-Contador N, Garcia-Rodas R. Cryptococcal Pathogenicity and Morphogenesis. CURRENT FUNGAL INFECTION REPORTS 2019. [DOI: 10.1007/s12281-019-00340-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Dragotakes Q, Fu MS, Casadevall A. Dragotcytosis: Elucidation of the Mechanism for Cryptococcus neoformans Macrophage-to-Macrophage Transfer. THE JOURNAL OF IMMUNOLOGY 2019; 202:2661-2670. [PMID: 30877168 DOI: 10.4049/jimmunol.1801118] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 02/27/2019] [Indexed: 12/11/2022]
Abstract
Cryptococcus neoformans is a pathogenic yeast capable of a unique and intriguing form of cell-to-cell transfer between macrophage cells. The mechanism for cell-to-cell transfer is not understood. In this study, we imaged mouse macrophages with CellTracker Green 5-chloromethylfluorescein diacetate-labeled cytosol to ascertain whether cytosol was shared between donor and acceptor macrophages. Analysis of several transfer events detected no transfer of cytosol from donor-to-acceptor mouse macrophages. However, blocking Fc and complement receptors resulted in a major diminution of cell-to-cell transfer events. The timing of cell-to-cell transfer (11.17 min) closely approximated the sum of phagocytosis (4.18 min) and exocytosis (6.71 min) times. We propose that macrophage cell-to-cell transfer represents a nonlytic exocytosis event, followed by phagocytosis into a macrophage that is in close proximity, and name this process Dragotcytosis ("Dragot" is a Greek surname meaning "sentinel"), as it represents sharing of a microbe between two sentinel cells of the innate immune system.
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Affiliation(s)
- Quigly Dragotakes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Man Shun Fu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
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Vechi HT, Theodoro RC, de Oliveira AL, Gomes RMODS, Soares RDDA, Freire MG, Bay MB. Invasive fungal infection by Cryptococcus neoformans var. grubii with bone marrow and meningeal involvement in a HIV-infected patient: a case report. BMC Infect Dis 2019; 19:220. [PMID: 30832607 PMCID: PMC6399886 DOI: 10.1186/s12879-019-3831-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 02/19/2019] [Indexed: 01/30/2023] Open
Abstract
Background Cryptococcosis is a common opportunistic infection in patients infected by Human Immunodeficiency Virus (HIV) and is the second leading cause of mortality in Acquired Immunodeficiency Syndrome (AIDS) patients worldwide. The most frequent presentation of cryptococcal infection is subacute meningitis, especially in patients with a CD4+ T Lymphocytes count below 100 cells/μL. However, in severely immunosuppressed individuals Cryptococcus neoformans can infect virtually any human organ, including the bone marrow, which is a rare presentation of cryptococcosis. Case presentation A 45-year-old HIV-infected male patient with a CD4+ T lymphocyte count of 26 cells/μL who presented to the emergency department with fever and pancytopenia. Throughout the diagnostic evaluation, the bone marrow aspirate culture yielded encapsulated yeasts in budding, identified as Cryptococcus sp. The bone marrow biopsy revealed a hypocellularity for age and absence of fibrosis. It was observed presence of loosely formed granuloma composed of multinucleated giant cells encompassing rounded yeast like organisms stained with mucicarmine, compatible with Cryptococcus sp. Then, the patient underwent a lumbar puncture to investigate meningitis, although he had no neurological symptoms and neurological examination was normal. The cerebrospinal fluid culture yielded Cryptococcus sp. The species and genotype identification step showed the infection was caused by Cryptococcus neoformans var. grubii (genotype VNI). The patient was initially treated with amphotericin B deoxycholate plus fluconazole for disseminated cryptococcosis, according to guideline recommendations. However, the patient developed acute kidney injury and the treatment was switched for fluconazole monotherapy. The symptoms disappeared completely with recovery of white blood cells and platelets counts. Cerebrospinal fluid cultures for fungi at one and two-weeks of treatment were negative. Conclusions Bone marrow infection caused by Cryptococcus neoformans is a rare presentation of cryptococcosis. The cryptococcal infection should be included for differential diagnosis in HIV-infected patients with fever and cytopenias, especially when CD4+ T lymphocytes count is below 100 cells/μL.
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Affiliation(s)
- Hareton Teixeira Vechi
- Department of Infectious Diseases, Hospital Giselda Trigueiro, Universidade Federal do Rio Grande do Norte, 110 Cônego Monte Street, Natal, Rio Grande do Norte, RN 59037-170, Brazil.
| | - Raquel Cordeiro Theodoro
- Department of Celular Biology and Genetics/Institute of Tropical Medicine, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, RN 59078-970, Brazil
| | - Andrea Lima de Oliveira
- Department of Celular Biology and Genetics/Institute of Tropical Medicine, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, RN 59078-970, Brazil
| | - Ronald Muryellison Oliveira da Silva Gomes
- Department of Celular Biology and Genetics/Institute of Tropical Medicine, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, RN 59078-970, Brazil
| | - Rodolfo Daniel de Almeida Soares
- Department of Hematology, Universidade Federal do Rio Grande do Norte, 619ª Nilo Peçanha Avenue, Natal, Rio Grande do Norte, RN 59012-300, Brazil
| | - Munya Gandour Freire
- Department of Pathology, Hospital Universitário Onofre Lopes, 600 Nilo Peçanha Avenue, Natal, Rio Grande do Norte, RN 59012-300, Brazil
| | - Mônica Baumgardt Bay
- Department of Infectious Diseases, Hospital Giselda Trigueiro, Universidade Federal do Rio Grande do Norte, 110 Cônego Monte Street, Natal, Rio Grande do Norte, RN 59037-170, Brazil
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Shourian M, Qureshi ST. Resistance and Tolerance to Cryptococcal Infection: An Intricate Balance That Controls the Development of Disease. Front Immunol 2019; 10:66. [PMID: 30761136 PMCID: PMC6361814 DOI: 10.3389/fimmu.2019.00066] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/11/2019] [Indexed: 12/25/2022] Open
Abstract
Cryptococcus neoformans is a ubiquitous environmental yeast and a leading cause of invasive fungal infection in humans. The most recent estimate of global disease burden includes over 200,000 cases of cryptococcal meningitis each year. Cryptococcus neoformans expresses several virulence factors that may have originally evolved to protect against environmental threats, and human infection may be an unintended consequence of these acquired defenses. Traditionally, C. neoformans has been viewed as a purely opportunistic pathogen that targets severely immune compromised hosts; however, during the past decade the spectrum of susceptible individuals has grown considerably. In addition, the closely related strain Cryptococcus gattii has recently emerged in North America and preferentially targets individuals with intact immunity. In parallel to the changing epidemiology of cryptococcosis, an increasing role for host immunity in the pathogenesis of severe disease has been elucidated. Initially, the HIV/AIDS epidemic revealed the capacity of C. neoformans to cause host damage in the absence of adaptive immunity. Subsequently, the development and clinical implementation of highly active antiretroviral treatment (HAART) led to recognition of an immune reconstitution inflammatory syndrome (IRIS) in a subset of HIV+ individuals, demonstrating the pathological role of host immunity in disease. A post-infectious inflammatory syndrome (PIIRS) characterized by abnormal T cell-macrophage activation has also been documented in HIV-negative individuals following antifungal therapy. These novel clinical conditions illustrate the highly complex host-pathogen relationship that underlies severe cryptococcal disease and the intricate balance between tolerance and resistance that is necessary for effective resolution. In this article, we will review current knowledge of the interactions between cryptococci and mammalian hosts that result in a tolerant phenotype. Future investigations in this area have potential for translation into improved therapies for affected individuals.
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Affiliation(s)
- Mitra Shourian
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Salman T Qureshi
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
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Brunet K, Alanio A, Lortholary O, Rammaert B. Reactivation of dormant/latent fungal infection. J Infect 2018; 77:463-468. [DOI: 10.1016/j.jinf.2018.06.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/23/2018] [Accepted: 06/25/2018] [Indexed: 12/18/2022]
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