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de Holanda Fonseca DL, Silva DMWD, de Albuquerque Maranhão FC. Molecular characterization of clinical and environmental isolates from the Cryptococcus neoformans/C. Gattii species complexes of Maceió, Alagoas, Brazil. Braz J Microbiol 2024; 55:1369-1380. [PMID: 38619732 PMCID: PMC11153433 DOI: 10.1007/s42770-024-01313-1] [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: 07/03/2023] [Accepted: 03/21/2024] [Indexed: 04/16/2024] Open
Abstract
Cryptococcosis is one of the major life-threatening opportunistic/systemic fungal diseases of worldwide occurrence, which can be asymptomatic or establish pneumonia and meningoencephalitis mainly in immunosuppressed patients, caused by the Cryptococcus neoformans and C. gattii species complexes. Acquisition is by inhaling fungal propagules from avian droppings, tree hollows and decaying wood, and the association of the molecular types with geographic origin, virulence and antifungal resistance have epidemiological importance. Since data on cryptococcosis in Alagoas are limited, we sought to determine the molecular types of etiological agents collected from clinical and environmental sources. We evaluated 21 isolates previously collected from cerebrospinal fluid and from environment sources (pigeon droppings and tree hollows) in Maceió-Alagoas (Brazil). Restriction fragment length polymorphism of URA5 gene was performed to characterize among the eight standard molecular types (VNI-VNIV and VGI-VGIV). Among isolates, 66.67% (14) were assigned to C. neoformans VNI - 12 of them (12/14) recovered from liquor and 2 from a tree hollow (2/14). One isolate from pigeon droppings (4.76%) corresponded to C. neoformans VNIV, while five strains from tree hollows and one from pigeon droppings (6, 28.57%) to C. gattii VGII. VNI-type was present in clinical and environmental samples and most C. neoformans infections were observed in HIV-positive patients, while types VNIV and VGII were prevalent in environmental sources in Alagoas. This is the first molecular characterization of Cryptococcus spp. in Alagoas, our study provides additional information on the ecoepidemiology of Cryptococcus spp. in Brazil, contributing to a closer view of the endemic species.
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Affiliation(s)
| | - Denise Maria Wanderlei da Silva
- Institute of Biological and Health Sciences, Sector of Microbiology, Laboratory of Clinical Microbiology, Federal University of Alagoas, Maceió, Alagoas, Brazil
| | - Fernanda Cristina de Albuquerque Maranhão
- Institute of Biological and Health Sciences, Sector of Microbiology, Laboratory of Clinical Microbiology, Federal University of Alagoas, Av. Lourival de Melo Mota, S/N, Tabuleiro do Martins, Maceió, 57072-900, Alagoas, Brazil.
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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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Hallas-Mølle M, Burow M, Henrissat B, Johansen KS. Cryptococcus neoformans: plant-microbe interactions and ecology. Trends Microbiol 2024:S0966-842X(24)00059-3. [PMID: 38519353 DOI: 10.1016/j.tim.2024.03.002] [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: 01/23/2024] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 03/24/2024]
Abstract
While the opportunistic human pathogens Cryptococcus neoformans and Cryptococcus gattii are often isolated from plants and plant-related material, evidence suggests that these Cryptococcus species do not directly infect plants. Studies find that plants are important for Cryptococcus mating and dispersal. However, these studies have not provided enough detail about how plants and these fungi interact, especially in ways that could show the fungi are capable of causing disease. This review synthesizes recent findings from studies utilizing different plant models associated with the ecology of C. neoformans and C. gattii. Unanswered questions about their environmental role are highlighted. Overall, current research indicates that Cryptococcus utilizes plants as a substrate rather than harming them, arguing against Cryptococcus as a genuine plant pathogen. We hypothesize that plants represent reservoirs that aid dispersal, not hosts vulnerable to infection.
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Affiliation(s)
- Magnus Hallas-Mølle
- Department of Geoscience and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - Meike Burow
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Bernard Henrissat
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kgs, Lyngby, Denmark
| | - Katja Salomon Johansen
- Department of Geoscience and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark.
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Cohen DG, Wingert RA. Caught red feathered: infection from cockatoo to human and mice reveals genetic plasticity of Cryptococcus neoformans during mammalian passage. Tissue Barriers 2024:2309717. [PMID: 38282267 DOI: 10.1080/21688370.2024.2309717] [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: 12/15/2023] [Accepted: 12/28/2023] [Indexed: 01/30/2024] Open
Abstract
The fungus Cryptococcus neoformans is pervasive in our environment and causes the infectious disease cryptococcosis in humans, most commonly in immunocompromised patients. In addition to corroborating the avian origins of a case of cryptococcosis in an immunocompromised patient in 2000, a fascinating recent report has now characterized the genetic and phenotypic changes that occur in this C. neoformans during passage in mammalian hosts. Interestingly, mouse-passaged isolates showed differences in virulence factors ranging from capsule size, melanization, nonlytic macrophage exocytosis, and amoeba predation resistance as compared to the patient strain. Taken together, these results provide new insights about the relationship between mutations acquired during an infection and changes in virulence.
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Affiliation(s)
- Dorrian G Cohen
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Rebecca A Wingert
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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Hilbert ZA, Bednarek JM, Schwiesow MJW, Chung KY, Moreau CT, Brown JCS, Elde NC. Distinct pathways of adaptive evolution in Cryptococcus neoformans reveal a mutation in adenylyl cyclase with trade-offs for pathogenicity. Curr Biol 2023; 33:4136-4149.e9. [PMID: 37708888 PMCID: PMC10592076 DOI: 10.1016/j.cub.2023.08.054] [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: 04/06/2023] [Revised: 07/13/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023]
Abstract
Pathogenic fungi populate a wide range of environments and infect a diversity of host species. Despite this substantial biological flexibility, the impact of interactions between fungi and their hosts on the evolution of pathogenicity remains unclear. We studied how repeated interactions between the fungus Cryptococcus neoformans and relevant environmental and mammalian host cells-amoeba and mouse macrophages-shape the evolution of this model fungal pathogen. First, using a collection of clinical and environmental isolates of C. neoformans, we characterized a range of survival phenotypes for these strains when exposed to host cells of different species. We then performed serial passages of an environmentally isolated C. neoformans strain through either amoeba or macrophages for ∼75 generations to observe how these interactions select for improved replication within hosts. In one adapted population, we identified a single point mutation in the adenylyl cyclase gene, CAC1, that swept to fixation and confers a strong competitive advantage for growth inside macrophages. Strikingly, this growth advantage in macrophages is inversely correlated with disease severity during mouse infections, suggesting that adaptation to specific host niches can markedly reduce the pathogenicity of these fungi. These results raise intriguing questions about the influence of cyclic AMP (cAMP) signaling on pathogenicity and highlight the role of seemingly small adaptive changes in promoting fundamental shifts in the intracellular behavior and virulence of these important human pathogens.
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Affiliation(s)
- Zoë A Hilbert
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
| | - Joseph M Bednarek
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Mara J W Schwiesow
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Krystal Y Chung
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Christian T Moreau
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Jessica C S Brown
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Nels C Elde
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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Sephton-Clark P, Nguyen T, Hoa NT, Ashton P, van Doorn HR, Ly VT, Le T, Cuomo CA. Impact of pathogen genetics on clinical phenotypes in a population of Talaromyces marneffei from Vietnam. Genetics 2023; 224:iyad100. [PMID: 37226893 PMCID: PMC10411598 DOI: 10.1093/genetics/iyad100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 03/29/2023] [Accepted: 05/12/2023] [Indexed: 05/26/2023] Open
Abstract
Talaromycosis, a severe and invasive fungal infection caused by Talaromyces marneffei, is difficult to treat and impacts those living in endemic regions of Southeast Asia, India, and China. While 30% of infections result in mortality, our understanding of the genetic basis of pathogenesis for this fungus is limited. To address this, we apply population genomics and genome-wide association study approaches to a cohort of 336 T. marneffei isolates collected from patients who enrolled in the Itraconazole vs Amphotericin B for Talaromycosis trial in Vietnam. We find that isolates from northern and southern Vietnam form two distinct geographical clades, with isolates from southern Vietnam associated with increased disease severity. Leveraging longitudinal isolates, we identify multiple instances of disease relapse linked to unrelated strains, highlighting the potential for multistrain infections. In more frequent cases of persistent talaromycosis caused by the same strain, we identify variants arising over the course of patient infections that impact genes predicted to function in the regulation of gene expression and secondary metabolite production. By combining genetic variant data with patient metadata for all 336 isolates, we identify pathogen variants significantly associated with multiple clinical phenotypes. In addition, we identify genes and genomic regions under selection across both clades, highlighting loci undergoing rapid evolution, potentially in response to external pressures. With this combination of approaches, we identify links between pathogen genetics and patient outcomes and identify genomic regions that are altered during T. marneffei infection, providing an initial view of how pathogen genetics affects disease outcomes.
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Affiliation(s)
- Poppy Sephton-Clark
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Thu Nguyen
- Division of Infectious Diseases and International Health, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ngo Thi Hoa
- Oxford University Clinical Research Unit, Oxford University, Ho Chi Minh City 749000, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX37LG, UK
- Microbiology department and Biological Research Center, Pham Ngoc Thach University of Medicine, Ho Chi Minh City 740500, Vietnam
| | - Philip Ashton
- Veterinary and Ecological Sciences, Institute of Infection, University of Liverpool, Liverpool CH647TE, UK
| | - H Rogier van Doorn
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX37LG, UK
- Oxford University Clinical Research Unit, Oxford University, Hanoi 113000, Vietnam
| | - Vo Trieu Ly
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX37LG, UK
- Department of Medicine and Pharmacy, Hospital for Tropical Diseases, Ho Chi Minh City 749000, Vietnam
| | - Thuy Le
- Division of Infectious Diseases and International Health, Duke University School of Medicine, Durham, NC 27710, USA
- Tropical Medicine Research Center for Talaromycosis, Pham Ngoc Thach University of Medicine, Ho Chi Minh City 740500, Vietnam
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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Sephton-Clark P, Nguyen T, Hoa NT, Ashton P, van Doorn HR, Ly VT, Le T, Cuomo CA. Impact of pathogen genetics on clinical phenotypes in a population of Talaromyces marneffei from Vietnam. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.30.534926. [PMID: 37034632 PMCID: PMC10081260 DOI: 10.1101/2023.03.30.534926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Talaromycosis, a severe and invasive fungal infection caused by Talaromyces marneffei , is difficult to treat and impacts those living in endemic regions of southeast Asia, India, and China. While 30% of infections result in mortality, our understanding of the genetic basis of pathogenesis for this fungus is limited. To address this, we apply population genomics and genome wide association study approaches to a cohort of 336 T. marneffei isolates collected from patients who enrolled in the Itraconazole versus Amphotericin B for Talaromycosis (IVAP) trial in Vietnam. We find that isolates from northern and southern Vietnam form two distinct geographical clades, with isolates from southern Vietnam associated with increased disease severity. Leveraging longitudinal isolates, we identify multiple instances of disease relapse linked to unrelated strains, highlighting the potential for multi-strain infections. In more frequent cases of persistent talaromycosis caused by the same strain, we identify variants arising over the course of patient infections that impact genes predicted to function in the regulation of gene expression and secondary metabolite production. By combining genetic variant data with patient metadata for all 336 isolates, we identify pathogen variants significantly associated with multiple clinical phenotypes. In addition, we identify genes and genomic regions under selection across both clades, highlighting loci undergoing rapid evolution, potentially in response to external pressures. With this combination of approaches, we identify links between pathogen genetics and patient outcomes and identify genomic regions that are altered during T. marneffei infection, providing an initial view of how pathogen genetics affects disease outcomes.
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Affiliation(s)
- Poppy Sephton-Clark
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA 02142
| | - Thu Nguyen
- Division of Infectious Diseases and International Health, Duke University School of Medicine, Durham, North Carolina, USA 27710
| | - Ngo Thi Hoa
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom OX37LG
- Microbiology department and Biological Research Center, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Philip Ashton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, UK CH647TE
| | - H. Rogier van Doorn
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom OX37LG
- Oxford University Clinical Research Unit, Hanoi, Vietnam
| | - Vo Trieu Ly
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom OX37LG
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Thuy Le
- Division of Infectious Diseases and International Health, Duke University School of Medicine, Durham, North Carolina, USA 27710
- Tropical Medicine Research Center for Talaromycosis, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Christina A. Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA 02142
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