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Jimenez IA, Stempinski PR, Dragotakes Q, Greengo SD, Ramirez LS, Casadevall A. The buoyancy of cryptococcal cells and its implications for transport and persistence of Cryptococcus in aqueous environments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.20.595024. [PMID: 38826196 PMCID: PMC11142132 DOI: 10.1101/2024.05.20.595024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Cryptococcus is a genus of saprophytic fungi with global distribution. Two species complexes, C. neoformans and C. gattii, pose health risks to humans and animals. Cryptococcal infections result from inhalation of aerosolized spores and/or desiccated yeasts from terrestrial reservoirs such as soil, trees, and avian guano. More recently, C. gattii has been implicated in infections in marine mammals, suggesting that inhalation of liquid droplets or aerosols from the air-water interface is also an important, yet understudied, mode of respiratory exposure. Water transport has also been suggested to play a role in the spread of C. gattii from tropical to temperate environments. However, the dynamics of fungal survival, persistence, and transport via water have not been fully studied. The size of the cryptococcal capsule was previously shown to reduce cell density and increase buoyancy. Here, we demonstrate that cell buoyancy is also impacted by the salinity of the media in which cells are suspended, with formation of a halocline interface significantly slowing the rate of settling of cryptococcal cells through water, resulting in persistence of C. neoformans within 1 cm of the air-water interface for over 60 min and C. gattii for 4-6 h. Our data also showed that during culture in yeast peptone dextrose media (YPD), polysaccharide accumulating in the supernatant formed a raft that augmented buoyancy and further slowed settling of cryptococcal cells. These findings illustrate new mechanisms by which cryptococcal cells may persist in aquatic environments, with important implications for aqueous transport and pathogen exposure.
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Affiliation(s)
- Isabel A. Jimenez
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Piotr R. Stempinski
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Quigly Dragotakes
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Seth D. Greengo
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Lia Sanchez Ramirez
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
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Teman SJ, Gaydos JK, Norman SA, Huggins JL, Lambourn DM, Calambokidis J, Ford JKB, Hanson MB, Haulena M, Zabek E, Cottrell P, Hoang L, Morshed M, Garner MM, Raverty S. Epizootiology of a Cryptococcus gattii outbreak in porpoises and dolphins from the Salish Sea. DISEASES OF AQUATIC ORGANISMS 2021; 146:129-143. [PMID: 34672263 DOI: 10.3354/dao03630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cryptococcus gattii is a fungal pathogen that primarily affects the respiratory and nervous systems of humans and other animals. C. gattii emerged in temperate North America in 1999 as a multispecies outbreak of cryptococcosis in British Columbia (Canada) and Washington State and Oregon (USA), affecting humans, domestic animals, and wildlife. Here we describe the C. gattii epizootic in odontocetes. Cases of C. gattii were identified in 42 odontocetes in Washington and British Columbia between 1997 and 2016. Species affected included harbor porpoises Phocoena phocoena (n = 26), Dall's porpoises Phocoenoides dalli (n = 14), and Pacific white-sided dolphins Lagenorhynchus obliquidens (n = 2). The probable index case was identified in an adult male Dall's porpoise in 1997, 2 yr prior to the initial terrestrial outbreak. The spatiotemporal extent of the C. gattii epizootic was defined, and cases in odontocetes were found to be clustered around terrestrial C. gattii hotspots. Case-control analyses with stranded, uninfected odontocetes revealed that risk factors for infection were species (Dall's porpoises), age class (adult animals), and season (winter). This study suggests that mycoses are an emerging source of mortality for odontocetes, and that outbreaks may be associated with anthropogenic environmental disturbance.
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Affiliation(s)
- Sarah J Teman
- The SeaDoc Society, Karen C. Drayer Wildlife Health Center - Orcas Island Office, UC Davis School of Veterinary Medicine, Eastsound, WA 98245, USA
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Accounting for the Biological Complexity of Pathogenic Fungi in Phylogenetic Dating. J Fungi (Basel) 2021; 7:jof7080661. [PMID: 34436200 PMCID: PMC8400180 DOI: 10.3390/jof7080661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/11/2021] [Accepted: 08/11/2021] [Indexed: 11/17/2022] Open
Abstract
In the study of pathogen evolution, temporal dating of phylogenies provides information on when species and lineages may have diverged in the past. When combined with spatial and epidemiological data in phylodynamic models, these dated phylogenies can also help infer where and when outbreaks occurred, how pathogens may have spread to new geographic locations and/or niches, and how virulence or drug resistance has developed over time. Although widely applied to viruses and, increasingly, to bacterial pathogen outbreaks, phylogenetic dating is yet to be widely used in the study of pathogenic fungi. Fungi are complex organisms with several biological processes that could present issues with appropriate inference of phylogenies, clock rates, and divergence times, including high levels of recombination and slower mutation rates although with potentially high levels of mutation rate variation. Here, we discuss some of the key methodological challenges in accurate phylogeny reconstruction for fungi in the context of the temporal analyses conducted to date and make recommendations for future dating studies to aid development of a best practices roadmap in light of the increasing threat of fungal outbreaks and antifungal drug resistance worldwide.
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Edwards HM, Cogliati M, Kwenda G, Fisher MC. The need for environmental surveillance to understand the ecology, epidemiology and impact of Cryptococcus infection in Africa. FEMS Microbiol Ecol 2021; 97:6312494. [PMID: 34196370 PMCID: PMC8536938 DOI: 10.1093/femsec/fiab093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Our understanding of the pathogenic yeasts Cryptococcus neoformans and Cryptococcus gattii has been greatly enhanced by use of genome sequencing technologies. Found ubiquitously as saprotrophs in the environment, inhalation of infectious spores from these pathogens can lead to the disease cryptococcosis. Individuals with compromised immune systems are at particular risk, most notably those living with HIV/AIDS. Genome sequencing in combination with laboratory and clinical studies has revealed diverse lineages with important differences in their observed frequency, virulence and clinical outcomes. However, to date, genomic analyses have focused primarily on clinical isolates that represent only a subset of the diversity in the environment. Enhanced genomic surveillance of these yeasts in their native environments is needed in order to understand their ecology, biology and evolution and how these influence the epidemiology and pathophysiology of clinical disease. This is particularly relevant on the African continent from where global cryptococcal diversity may have originated, yet where environmental sampling and sequencing has been sparse despite harbouring the largest population at risk from cryptococcosis. Here, we review what scientifically and clinically relevant insights have been provided by analysis of environmental Cryptococcus isolates to date and argue that with further sampling, particularly in Africa, many more important discoveries await.
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Affiliation(s)
- Hannah M Edwards
- MRC Centre for Global Infectious Disease Analysis, Imperial College School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Massimo Cogliati
- Dip. Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Pascal 36, 20133 Milano, Italy
| | - Geoffrey Kwenda
- Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Ridgeway Campus, PO Box 50110, Lusaka, Zambia
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, Imperial College School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
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Bresciani FR, Santi L, Beys-da-Silva WO, Berger M, Barcellos VDA, Schripsema J, von Poser GL, Guimarães JA, Vainstein MH. Antifungal activity of Allamanda polyantha seed extract and its iridoids promote morphological alterations in Cryptococcus spp. Arch Pharm (Weinheim) 2020; 353:e2000133. [PMID: 32638423 DOI: 10.1002/ardp.202000133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/20/2022]
Abstract
Cryptococcosis, caused by Cryptococcus spp., is an invasive fungal infection of the central nervous system, associated with high mortality, affecting mainly immunocompromised patients. Due to the development of resistance to the current therapy, there is an urgent need for less toxic and more effective antifungal agents. In this study, we describe the antifungal activity against Cryptococcus spp. of an aqueous seed extract from Allamanda polyantha (ASEAP) and two iridoids, plumieride and plumieridine, isolated from this extract with an antifungal activity. The capsule formation and the morphological alterations were evaluated using fluorescent microscopy. The cytotoxic activity was also investigated. The minimal inhibitory concentration (MIC) values of ASEAP for Cryptococcus gattii were 70 and 36 µg/ml (for the R265 and R272 strains, respectively) and 563 µg/ml for Cryptococcus neoformans H99. ASEAP inhibited C. neoformans H99 capsule formation, an important virulence factor, and decreased the cell body size for both the C. gattii strains. H99 cells also presented morphological alterations, with defects in bud detachment and nuclear fragmentation. Plumieride and plumieridine presented higher MIC values than ASEAP, indicating that other compounds might contribute to antifungal activity and/or that combination of the compounds results in a higher antifungal activity.
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Affiliation(s)
- Fernanda R Bresciani
- Postgraduate Program in Cellular and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Lucélia Santi
- Postgraduate Program in Cellular and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.,Faculty of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.,Experimental Research Center, Clinical Hospital of Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Walter O Beys-da-Silva
- Postgraduate Program in Cellular and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.,Faculty of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.,Experimental Research Center, Clinical Hospital of Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Markus Berger
- Experimental Research Center, Clinical Hospital of Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Vanessa de A Barcellos
- Postgraduate Program in Cellular and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Jan Schripsema
- Metabolomics Group, State University of North Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Gilsane L von Poser
- Faculty of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Jorge A Guimarães
- Experimental Research Center, Clinical Hospital of Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Marilene H Vainstein
- Postgraduate Program in Cellular and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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Chakrabarti A, Meis JF, Cornely OA. International Society for Human and Animal Mycology (ISHAM)-New Initiatives. J Fungi (Basel) 2020; 6:jof6030097. [PMID: 32630110 PMCID: PMC7557397 DOI: 10.3390/jof6030097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 12/16/2022] Open
Abstract
Fungal infections have emerged as major threat to human beings. The world is not ready to face this formidable challenge due to limited awareness, insufficient laboratories, and difficulty in managing mycoses especially in developing countries. The International Society for Human and Animal Mycology (ISHAM) has undertaken several new initiatives to overcome these gaps, including a global outreach program with national affiliated mycology societies and other regional groups. ISHAM is working closely with the European Confederation of Medical Mycology (ECMM) and Global Action Fund for Fungal Infections (GAFFI) to enhance these efforts. The society has launched laboratory e-courses and is in the process of the development of clinical e-courses. ISHAM has partnered with regional conferences in South America and Asia by sponsoring international experts and young delegates. The society also supports young people from less developed countries to undergo training in laboratories of excellence. ISHAM facilitated the formation of the INFOCUSLatin American Clinical Mycology Working Group (LATAM) and the Pan-African Mycology Working Group. The society appointed country ambassadors to facilitate coordination with national societies. Still, the task is enormous and ISHAM calls for strong advocacy and more coordinated activities to attract the attention of people from all disciplines to this neglected field.
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Affiliation(s)
- Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
- Correspondence:
| | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital (CWZ), 6532 SZ Nijmegen, The Netherlands;
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
- Bioprocess Engineering and Biotechnology Graduate Program, Federal University of Paraná, Curitiba 81531-970, Brazil
| | - Oliver A. Cornely
- Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Medical Faculty and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany;
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
- Zentrum fuer klinische Studien (ZKS) Köln, Clinical Trials Centre Cologne, University of Cologne, 50935 Cologne, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Medical Faculty and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
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7
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Chow NA, Muñoz JF, Gade L, Berkow EL, Li X, Welsh RM, Forsberg K, Lockhart SR, Adam R, Alanio A, Alastruey-Izquierdo A, Althawadi S, Araúz AB, Ben-Ami R, Bharat A, Calvo B, Desnos-Ollivier M, Escandón P, Gardam D, Gunturu R, Heath CH, Kurzai O, Martin R, Litvintseva AP, Cuomo CA. Tracing the Evolutionary History and Global Expansion of Candida auris Using Population Genomic Analyses. mBio 2020; 11:e03364-19. [PMID: 32345637 PMCID: PMC7188998 DOI: 10.1128/mbio.03364-19] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/01/2020] [Indexed: 01/26/2023] Open
Abstract
Candida auris has emerged globally as a multidrug-resistant yeast that can spread via nosocomial transmission. An initial phylogenetic study of isolates from Japan, India, Pakistan, South Africa, and Venezuela revealed four populations (clades I, II, III, and IV) corresponding to these geographic regions. Since this description, C. auris has been reported in more than 30 additional countries. To trace this global emergence, we compared the genomes of 304 C. auris isolates from 19 countries on six continents. We found that four predominant clades persist across wide geographic locations. We observed phylogeographic mixing in most clades; clade IV, with isolates mainly from South America, demonstrated the strongest phylogeographic substructure. C. auris isolates from two clades with opposite mating types were detected contemporaneously in a single health care facility in Kenya. We estimated a Bayesian molecular clock phylogeny and dated the origin of each clade within the last 360 years; outbreak-causing clusters from clades I, III, and IV originated 36 to 38 years ago. We observed high rates of antifungal resistance in clade I, including four isolates resistant to all three major classes of antifungals. Mutations that contribute to resistance varied between the clades, with Y132F in ERG11 as the most widespread mutation associated with azole resistance and S639P in FKS1 for echinocandin resistance. Copy number variants in ERG11 predominantly appeared in clade III and were associated with fluconazole resistance. These results provide a global context for the phylogeography, population structure, and mechanisms associated with antifungal resistance in C. aurisIMPORTANCE In less than a decade, C. auris has emerged in health care settings worldwide; this species is capable of colonizing skin and causing outbreaks of invasive candidiasis. In contrast to other Candida species, C. auris is unique in its ability to spread via nosocomial transmission and its high rates of drug resistance. As part of the public health response, whole-genome sequencing has played a major role in characterizing transmission dynamics and detecting new C. auris introductions. Through a global collaboration, we assessed genome evolution of isolates of C. auris from 19 countries. Here, we described estimated timing of the expansion of each C. auris clade and of fluconazole resistance, characterized discrete phylogeographic population structure of each clade, and compared genome data to sensitivity measurements to describe how antifungal resistance mechanisms vary across the population. These efforts are critical for a sustained, robust public health response that effectively utilizes molecular epidemiology.
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Affiliation(s)
- Nancy A Chow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - José F Muñoz
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Lalitha Gade
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Elizabeth L Berkow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Xiao Li
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Rory M Welsh
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Kaitlin Forsberg
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Rodney Adam
- Department of Pathology, Aga Khan University Hospital, Nairobi, Kenya
| | - Alexandre Alanio
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, National Reference Center for Invasive Mycoses and Antifungals (NRCMA), 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, Université de Paris, Paris, France
| | - Ana Alastruey-Izquierdo
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Sahar Althawadi
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | - Ronen Ben-Ami
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Amrita Bharat
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Belinda Calvo
- Department of Infectious Diseases, School of Medicine, Universidad del Zulia, Maracaibo, Venezuela
| | - Marie Desnos-Ollivier
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, National Reference Center for Invasive Mycoses and Antifungals (NRCMA), Paris, France
| | - Patricia Escandón
- Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, Colombia
| | - Dianne Gardam
- Department of Microbiology, PathWest Laboratory Medicine FSH Network, Fiona Stanley Hospital, Murdoch, Australia
| | - Revathi Gunturu
- Department of Pathology, Aga Khan University Hospital, Nairobi, Kenya
| | - Christopher H Heath
- Department of Microbiology, PathWest Laboratory Medicine FSH Network, Fiona Stanley Hospital, Murdoch, Australia
- Department of Infectious Diseases, Fiona Stanley Hospital, Murdoch, Australia
- Infectious Diseases, Royal Perth Hospital, Perth, Australia
- Faculty of Health & Medical Sciences, University of Western Australia, Crawley, Washington, Australia
| | - Oliver Kurzai
- German National Reference Center for Invasive Fungal Infections NRZMyk, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Jena, Germany
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Ronny Martin
- German National Reference Center for Invasive Fungal Infections NRZMyk, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Jena, Germany
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Anastasia P Litvintseva
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
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Abstract
Discovering that chytrid fungi cause chytridiomycosis in amphibians represented a paradigm shift in our understanding of how emerging infectious diseases contribute to global patterns of biodiversity loss. In this Review we describe how the use of multidisciplinary biological approaches has been essential to pinpointing the origins of amphibian-parasitizing chytrid fungi, including Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, as well as to timing their emergence, tracking their cycles of expansion and identifying the core mechanisms that underpin their pathogenicity. We discuss the development of the experimental methods and bioinformatics toolkits that have provided a fuller understanding of batrachochytrid biology and informed policy and control measures.
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Engelthaler DM, Casadevall A. On the Emergence of Cryptococcus gattii in the Pacific Northwest: Ballast Tanks, Tsunamis, and Black Swans. mBio 2019; 10:e02193-19. [PMID: 31575770 PMCID: PMC6775458 DOI: 10.1128/mbio.02193-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The appearance of Cryptococcus gattii in the North American Pacific Northwest (PNW) in 1999 was an unexpected and is still an unexplained event. Recent phylogenomic analyses strongly suggest that this pathogenic fungus arrived in the PNW approximately 7 to 9 decades ago. In this paper, we theorize that the ancestors of the PNW C. gattii clones arrived in the area by shipborne transport, possibly in contaminated ballast, and established themselves in coastal waters early in the 20th century. In 1964, a tsunami flooded local coastal regions, transporting C. gattii to land. The occurrence of cryptococcosis in animals and humans 3 decades later suggests that adaptation to local environs took time, possibly requiring an increase in virulence and further dispersal. Tsunamis as a mechanism for the seeding of land with pathogenic waterborne microbes may have important implications for our understanding of how infectious diseases emerge in certain regions. This hypothesis suggests experimental work for its validation or refutation.
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Rickerts V. [Climate change and systemic fungal infections]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2019; 62:646-651. [PMID: 30923845 DOI: 10.1007/s00103-019-02931-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Climate change may cause profound and complex changes in the prevalence of infectious diseases. Obligate pathogenic fungi causing endemic mycoses and the agents of cryptococcosis are environmental pathogens adapted to environmental niches. They may be exposed to changing climatic conditions, which may change the epidemiology of human infections. OBJECTIVES To review documented changes in the epidemiology of endemic fungal infections and cryptococcosis. To review evidence that changing climate is a potential mechanism for changes in the epidemiology of these infections. METHODS A selective literature review focusing on endemic mycoses and cryptococcosis. RESULTS Changes in endemic regions of infections caused by C. gattii and selected endemic mycoses have been well documented. Significant increases in the incidence of infections have been demonstrated for some areas. Climatic factors (temperature, precipitation, and extreme weather events), changes in land use, distribution of potential host animals, and global trade routes are discussed as contributory factors. CONCLUSIONS Improved surveillance of fungal infections of humans and animals including molecular typing of clinical and environmental isolates is necessary to understand the epidemiology of these infections. The characterization of environmental niches, mechanisms of distribution of fungi, and fungal adaptation mechanisms are needed to guide prevention strategies.
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Affiliation(s)
- Volker Rickerts
- FG 16, Erreger von Mykosen, Mykobakteriosen und Parasitosen, Konsiliarlabor für Kryptokokkose und seltene Systemmykosen, Robert Koch-Institut, Seestraße 10, 13353, Berlin, Deutschland.
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11
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Beardsley J, Sorrell TC, Chen SCA. Central Nervous System Cryptococcal Infections in Non-HIV Infected Patients. J Fungi (Basel) 2019; 5:jof5030071. [PMID: 31382367 PMCID: PMC6787755 DOI: 10.3390/jof5030071] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/22/2019] [Accepted: 07/29/2019] [Indexed: 12/27/2022] Open
Abstract
Central nervous system (CNS) cryptococcosis in non-HIV infected patients affects solid organ transplant (SOT) recipients, patients with malignancy, rheumatic disorders, other immunosuppressive conditions and immunocompetent hosts. More recently described risks include the use of newer biologicals and recreational intravenous drug use. Disease is caused by Cryptococcus neoformans and Cryptococcus gattii species complex; C. gattii is endemic in several geographic regions and has caused outbreaks in North America. Major virulence determinants are the polysaccharide capsule, melanin and several ‘invasins’. Cryptococcal plb1, laccase and urease are essential for dissemination from lung to CNS and crossing the blood–brain barrier. Meningo-encephalitis is common but intracerebral infection or hydrocephalus also occur, and are relatively frequent in C. gattii infection. Complications include neurologic deficits, raised intracranial pressure (ICP) and disseminated disease. Diagnosis relies on culture, phenotypic identification methods, and cryptococcal antigen detection. Molecular methods can assist. Preferred induction antifungal therapy is a lipid amphotericin B formulation (amphotericin B deoxycholate may be used in non-transplant patients) plus 5-flucytosine for 2–6 weeks depending on host type followed by consolidation/maintenance therapy with fluconazole for 12 months or longer. Control of raised ICP is essential. Clinicians should be vigilant for immune reconstitution inflammatory syndrome.
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Affiliation(s)
- Justin Beardsley
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney 2145, Australia
| | - Tania C Sorrell
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney 2145, Australia
- Westmead Institute for Medical Research, Westmead, Sydney 2145, Australia
| | - Sharon C-A Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead Hospital and the Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney 2145, Australia.
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Abstract
Cryptococcus gattii molecular type VGII is one of the etiologic agents of cryptococcosis, a systemic mycosis affecting a wide range of host species. Koalas (Phascolarctos cinereus) exhibit a comparatively high prevalence of cryptococcosis (clinical and subclinical) and nasal colonization, particularly in captivity. In Australia, disease associated with C. gattii VGII is typically confined to Western Australia and the Northern Territory (with sporadic cases reported in eastern Australia), occupying an enigmatic ecologic niche. A cluster of cryptococcosis in captive koalas in eastern Australia (five confirmed cases, a further two suspected), caused predominantly by C. gattii VGII, was investigated by surveying for subclinical disease, culturing koala nasal swabs and environmental samples, and genotyping cryptococcal isolates. URA5 restriction fragment length polymorphism analysis, multilocus sequence typing (MLST), and whole-genome sequencing (WGS) provided supportive evidence that the transfer of koalas from Western Australia and subsequently between several facilities in Queensland spread VGII into uncontaminated environments and environments in which C. gattii VGI was endemic. MLST identified VGII isolates as predominantly sequence type 7, while WGS further confirmed a limited genomic diversity and revealed a basal relationship with isolates from Western Australia. We hypothesize that this represents a founder effect following the introduction of a koala from Western Australia. Our findings suggest a possible competitive advantage for C. gattii VGII over VGI in the context of this captive koala environment. The ability of koalas to seed C. gattii VGII into new environments has implications for the management of captive populations and movements of koalas between zoos.IMPORTANCE Cryptococcus gattii molecular type VGII is one of the causes of cryptococcosis, a severe fungal disease that is acquired from the environment and affects many host species (including humans and koalas). In Australia, disease caused by C. gattii VGII is largely confined to western and central northern parts of the country, with sporadic cases reported in eastern Australia. We investigated an unusual case cluster of cryptococcosis, caused predominantly by C. gattii VGII, in a group of captive koalas in eastern Australia. This research identified that the movements of koalas between wildlife parks, including an initial transfer of a koala from Western Australia, introduced and subsequently spread C. gattii VGII in this captive environment. The spread of this pathogen by koalas could also impact other species, and these findings are significant in the implications they have for the management of koala transfers and captive environments.
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Aleksic Sabo V, Knezevic P. Antimicrobial activity of Eucalyptus camaldulensis Dehn. plant extracts and essential oils: A review. INDUSTRIAL CROPS AND PRODUCTS 2019; 132:413-429. [PMID: 32288268 PMCID: PMC7126574 DOI: 10.1016/j.indcrop.2019.02.051] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/20/2019] [Accepted: 02/24/2019] [Indexed: 05/15/2023]
Abstract
Eucalyptus has become one of the world's most widely planted genera and E. camaldulensis (The River Red Gum) is a plantation species in many parts of the world. The plant traditional medical application indicates great antimicrobial properties, so E. camaldulensis essential oils and plant extracts have been widely examined. Essential oil of E. camaldulensis is active against many Gram positive (0.07-1.1%) and Gram negative bacteria (0.01-3.2%). The antibacterial effect is confirmed for bark and leaf extracts (conc. from 0.08 μg/mL to 200 mg/mL), with significant variations depending on extraction procedure. Eucalyptus camaldulensis essential oil and extracts are among the most active against bacteria when compared with those from other species of genus Eucalyptus. The most fungal model organisms are sensitive to 0.125-1.0% of E. camaldulensis essential oil. The extracts are active against C. albicans (0.2-200 mg/mL leaf extracts and 0.5 mg/mL bark extracts), and against various dermatophytes. Of particular importance is considerable the extracts' antiviral activity against animal and human viruses (0.1-50 μg/mL). Although the antiprotozoal activity of E. camaldulensis essential oil and extracts is in the order of magnitude of concentration several hundred mg/mL, it is considerable when taking into account current therapy cost, toxicity, and protozoal growing resistance. Some studies show that essential oils' and extracts' antimicrobial activity can be further potentiated in combinations with antibiotics (beta-lactams, fluorochinolones, aminoglycosides, polymyxins), antivirals (acyclovir), and extracts of other plants (e.g. Annona senegalensis; Psidium guajava). The present data confirm the river red gum considerable antimicrobial properties, which should be further examined with particular attention to the mechanisms of antimicrobial activity.
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Affiliation(s)
- Verica Aleksic Sabo
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 2, Novi Sad, Vojvodina, Serbia
| | - Petar Knezevic
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 2, Novi Sad, Vojvodina, Serbia
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Lockhart SR, Roe CC, Engelthaler DM. Timing the Origin of Cryptococcus gattii sensu stricto, Southeastern United States. Emerg Infect Dis 2019; 24:2095-2097. [PMID: 30334716 PMCID: PMC6200013 DOI: 10.3201/eid2411.180975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We conducted molecular clock analysis of whole-genome sequences from a set of autochthonous isolates of Cryptococcus gattii sensu stricto from the southeastern United States. Our analysis indicates that C. gattii arrived in the southeastern United States approximately 9,000–19,000 years ago, long before its arrival in the Pacific Northwest.
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Cogliati M, Desnos-Ollivier M, McCormick-Smith I, Rickerts V, Ferreira-Paim K, Meyer W, Boekhout T, Hagen F, Theelen B, Inácio J, Alonso B, Colom MF, Trilles L, Montagna MT, De Donno A, Susever S, Ergin C, Velegraki A, Ellabib MS, Nardoni S, Macci C, Trovato L, Dipineto L, Akcaglar S, Mlinaric-Missoni E, Bertout S, Vencá ACF, Sampaio AC, Criseo G, Ranque S, Çerikçioğlu N, Marchese A, Vezzulli L, Ilkit M, Pasquale V, Polacheck I, Lockhart SR. Genotypes and population genetics of cryptococcus neoformans and cryptococcus gattii species complexes in Europe and the mediterranean area. Fungal Genet Biol 2019; 129:16-29. [PMID: 30953839 DOI: 10.1016/j.fgb.2019.04.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 02/06/2023]
Abstract
A total of 476 European isolates (310 Cryptococcus neoformans var. grubii, 150 C. neoformans var. neoformans, and 16 C. gattii species complex) from both clinical and environmental sources were analyzed by multi-locus sequence typing. Phylogenetic and population genetic analyses were performed. Sequence analysis identified 74 sequence types among C. neoformans var. neoformans (VNIV), 65 among C. neoformans var. grubii (56 VNI, 8 VNII, 1 VNB), and 5 among the C. gattii species complex (4 VGI and 1 VGIV) isolates. ST23 was the most frequent genotype (22%) among VNI isolates which were mostly grouped in a large clonal cluster including 50% of isolates. Among VNIV isolates, a predominant genotype was not identified. A high percentage of autochthonous STs were identified in both VNI (71%) and VNIV (96%) group of isolates. The 16 European C. gattii species complex isolates analyzed in the present study originated all from the environment and all belonged to a large cluster endemic in the Mediterranean area. Population genetic analysis confirmed that VNI group of isolates were characterized by low variability and clonal expansion while VNIV by a higher variability and a number of recombination events. However, when VNI and VNIV environmental isolates were compared, they showed a similar population structure with a high percentage of shared mutations and the absence of fixed mutations. Also linkage disequilibrium analysis reveals differences between clinical and environmental isolates showing a key role of PLB1 allele combinations in host infection as well as the key role of LAC1 allele combinations for survival of the fungus in the environment. The present study shows that genetic comparison of clinical and environmental isolates represents a first step to understand the genetic characteristics that cause the shift of some genotypes from a saprophytic to a parasitic life style.
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Affiliation(s)
- Massimo Cogliati
- Dip. Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano, Italy.
| | - Marie Desnos-Ollivier
- Institut Pasteur, Molecular Mycology Unit, National Reference Center for Invasive Mycoses & Antifungal, CNRS UMR2000, Paris, France
| | | | | | - Kennio Ferreira-Paim
- Molecular Mycology Research Laboratory, Center for Infectious Diseases, Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical School, Marie Bashier Institute for Emerging Infectious Diseases and Biosecurity, University of Sydney, Westmead Hospital, (Research and Educational Network) Westmead Institute for Medical Research, Westmead, NSW, Australia; Department of Microbiology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Center for Infectious Diseases, Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical School, Marie Bashier Institute for Emerging Infectious Diseases and Biosecurity, University of Sydney, Westmead Hospital, (Research and Educational Network) Westmead Institute for Medical Research, Westmead, NSW, Australia
| | - Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands; Institute of Biodiversity and Ecosystem Dynamic (IBED), University of Amsterdam, Amsterdam, the Netherlands
| | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - Bart Theelen
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - Joäo Inácio
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Beatriz Alonso
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK; Instituto de Investigación Sanitaria Gregorio Marañón (IisGM), Hospital Gegorio Marañón, Madrid, Spain
| | | | | | | | | | | | | | - Aristea Velegraki
- Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | | | - Cristina Macci
- National Research Council, Research Institute on Terrestrial Ecosystems (IRET), Pisa, Italy
| | | | | | | | | | - Sebastien Bertout
- Unité Mixte Internationale "Recherches Translationnelles sur l'infection à VIH et les Maladies Infectieuses", Université de Montpellier, Montpellier, France
| | - Ana C F Vencá
- Instituto de Higiene e Medicina Tropical, Lisbon, Portugal
| | - Ana C Sampaio
- Universidade de Trás-os-Montes e Alto Douro, CITAB, Quinta dos Prados, Vila Real, Portugal
| | - Giuseppe Criseo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy
| | - Stéphane Ranque
- Aix-Marseille University, IRD, APHM, SSA, VITROME, IHU-Méditerranée Infection, Marseille, France
| | | | - Anna Marchese
- Sezione di Microbiologia del DISC, Università di Genova-IRCCS Policlinico San Martino Genova, Genova, Italy
| | - Luigi Vezzulli
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita (DISTAV), Università di Genova, Genova, Italy
| | - Macit Ilkit
- University of Çukurova Sarıçam, Adana, Turkey
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Cryptococcus deuterogattii VGIIa Infection Associated with Travel to the Pacific Northwest Outbreak Region in an Anti-Granulocyte-Macrophage Colony-Stimulating Factor Autoantibody-Positive Patient in the United States. mBio 2019; 10:mBio.02733-18. [PMID: 30755511 PMCID: PMC6372798 DOI: 10.1128/mbio.02733-18] [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] [Indexed: 12/13/2022] Open
Abstract
Mortality rates associated with C. gattii infections are estimated to be between 13% and 33%, depending on an individual’s predisposition, and C. gattii has caused at least 39 deaths in the PNW region. There have been four other international travel cases reported in patients from Europe and Asia with travel history to the PNW, but this report describes the first North American traveler who acquired C. deuterogattii infection presenting within the United States and the first case of a C. deuterogattii outbreak infection associated with anti-GM-CSF autoantibodies. Early and accurate diagnoses are important for disease prevention and treatment and for control of infectious diseases. Continual reporting of C. deuterogattii infections is necessary to raise awareness of the ongoing outbreak in the PNW and to alert travelers and physicians to the areas of endemicity with potential risks. The region encompassing the Pacific Northwest (PNW), Vancouver Island, Oregon, and Washington has been the location of an ongoing Cryptococcus gattii outbreak since the 1990s, and there is evidence that the outbreak is expanding along the West Coast into California. Here we report a clinical case of a 69-year-old, HIV-negative man from North Carolina who was diagnosed with a fungal brain mass by magnetic resonance imaging (MRI) and pathology. He had traveled to Seattle and Vancouver 3 years earlier and to Costa Rica 4 months prior to presentation. Phenotypic evidence showed that the fungal mass isolated from the patient’s brain represented C. gattii. In agreement with the phenotypic results, multilocus sequence typing (MLST) provided genotypic evidence that assigned the infecting organism within the C. gattii species complex and to the C. deuterogattii VGIIa clade. Whole-genome sequencing revealed >99.99% identity with the C. deuterogattii reference strain R265, indicating that the infecting strain is derived from the highly clonal outbreak strains in the PNW. We conclude that the patient acquired the C. gattii infection during his travel to the region 3 years prior and that the infection was dormant for an extended period of time before causing disease. The patient tested positive for anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, supporting earlier reports that implicate these autoantibodies as a risk factor associated with C. gattii infection.
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Vij R, Cordero RJB, Casadevall A. The Buoyancy of Cryptococcus neoformans Is Affected by Capsule Size. mSphere 2018; 3:e00534-18. [PMID: 30404928 PMCID: PMC6222054 DOI: 10.1128/msphere.00534-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 10/17/2018] [Indexed: 12/16/2022] Open
Abstract
Cryptococcus neoformans is an environmental pathogenic fungus with a worldwide geographical distribution that is responsible for hundreds of thousands of human cryptococcosis cases each year. During infection, the yeast undergoes a morphological transformation involving capsular enlargement that increases microbial volume. To understand the factors that play a role in environmental dispersal of C. neoformans and C. gattii, we evaluated the cell density of Cryptococcus using Percoll isopycnic gradients. We found differences in the cell densities of strains belonging to C. neoformans and C. gattii species complexes. The buoyancy of C. neoformans strains varied depending on growth medium. In minimal medium, the cryptococcal capsule made a major contribution to the cell density such that cells with larger capsules had lower density than those with smaller capsules. Removing the capsule, by chemical or mechanical methods, increased the C. neoformans cell density and reduced buoyancy. Melanization of the C. neoformans cell wall, which also contributes to virulence, produced a small but consistent increase in cell density. Encapsulated C. neoformans sedimented much more slowly in seawater as its density approached the density of water. Our results suggest a new function for the capsule whereby it can function as a flotation device to facilitate transport and dispersion in aqueous fluids.IMPORTANCE The buoyancy of a microbial cell is an important physical characteristic that may affect its transportability in fluids and interactions with tissues during infection. The polysaccharide capsule surrounding C. neoformans is required for infection and dissemination in the host. Our results indicate that the capsule has a significant effect on reducing cryptococcal cell density, altering its sedimentation in seawater. Modulation of microbial cell density via encapsulation may facilitate dispersal for other important encapsulated pathogens.
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Affiliation(s)
- Raghav Vij
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Radames J B Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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