1
|
Chadwick BJ, Lin X. Effects of CO 2 in fungi. Curr Opin Microbiol 2024; 79:102488. [PMID: 38759247 PMCID: PMC11162916 DOI: 10.1016/j.mib.2024.102488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 04/21/2024] [Accepted: 04/25/2024] [Indexed: 05/19/2024]
Abstract
Carbon dioxide supplies carbon for photosynthetic species and is a major product of respiration for all life forms. Inside the human body where CO2 is a by-product of the tricarboxylic acid cycle, its level reaches 5% or higher. In the ambient atmosphere, ∼.04% of the air is CO2. Different organisms can tolerate different CO2 levels to various degrees, and experiencing higher CO2 is toxic and can lead to death. The fungal kingdom shows great variations in response to CO2 that has been documented by different researchers at different time periods. This literature review aims to connect these studies, highlight mechanisms underlying tolerance to high levels of CO2, and emphasize the effects of CO2 on fungal metabolism and morphogenesis.
Collapse
Affiliation(s)
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
| |
Collapse
|
2
|
Konkel Neabore L. Wake-up Call: Rapid Increase in Human Fungal Diseases under Climate Change. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:42001. [PMID: 38648197 PMCID: PMC11034633 DOI: 10.1289/ehp14722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 02/28/2024] [Indexed: 04/25/2024]
Abstract
Rising temperatures and extreme weather are setting the stage for increases in fungal diseases. As new pathogenic fungi emerge and known threats spread and evolve, scientists and decision makers are responding.
Collapse
|
3
|
Sephton-Clark P, Temfack E, Tenor JL, Toffaletti DL, Loyse A, Molloy SF, Perfect JR, Bicanic T, Harrison TS, Lortholary O, Kouanfack C, Cuomo CA. Genetic diversity and microevolution in clinical Cryptococcus isolates from Cameroon. Med Mycol 2023; 61:myad116. [PMID: 37952096 PMCID: PMC10709296 DOI: 10.1093/mmy/myad116] [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: 08/22/2023] [Revised: 11/03/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023] Open
Abstract
Cryptococcal meningitis is the second most common cause of death in people living with HIV/AIDS, yet we have a limited understanding of how cryptococcal isolates change over the course of infection. Cryptococcal infections are environmentally acquired, and the genetic diversity of these infecting isolates can also be geographically linked. Here, we employ whole genome sequences for 372 clinical Cryptococcus isolates from 341 patients with HIV-associated cryptococcal meningitis obtained via a large clinical trial, across both Malawi and Cameroon, to enable population genetic comparisons of isolates between countries. We see that isolates from Cameroon are highly clonal, when compared to those from Malawi, with differential rates of disruptive variants in genes with roles in DNA binding and energy use. For a subset of patients (22) from Cameroon, we leverage longitudinal sampling, with samples taken at days 7 and 14 post-enrollment, to interrogate the genetic changes that arise over the course of infection, and the genetic diversity of isolates within patients. We see disruptive variants arising over the course of infection in several genes, including the phagocytosis-regulating transcription factor GAT204. In addition, in 13% of patients sampled longitudinally, we see evidence for mixed infections. This approach identifies geographically linked genetic variation, signatures of microevolution, and evidence for mixed infections across a clinical cohort of patients affected by cryptococcal meningitis in Central Africa.
Collapse
Affiliation(s)
- Poppy Sephton-Clark
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Elvis Temfack
- Internal Medicine Unit, Douala General Hospital, Douala, Cameroon
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR 2000, Paris, France
| | - 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
| | - Angela Loyse
- Institute of Infection and Immunity, St George's University of London, London, UK
- Clinical Academic Group in Infection, St George's University Hospital, London, UK
| | - Síle F Molloy
- Institute of Infection and Immunity, St George's University of London, London, UK
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Tihana Bicanic
- Institute of Infection and Immunity, St George's University of London, London, UK
- Clinical Academic Group in Infection, St George's University Hospital, London, UK
| | - Thomas S Harrison
- Institute of Infection and Immunity, St George's University of London, London, UK
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Olivier Lortholary
- Department of Infectious Diseases and Tropical Medicine, Paris Cité University, Necker-Enfants Malades Hospital, AP-HP, IHU Imagine, Paris, France
- Mycology Department and National Reference Center for Invasive Mycoses and Antifungals, Institut Pasteur, Paris, France
| | - Charles Kouanfack
- Department of Public Health, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Dschang, Cameroon
- Day Hospital, Hospital Central Yaoundé, Yaoundé, Cameroon
- Research Center for Emerging and Re-emerging Diseases, Cameroon Baptist Convention Health Services (CBCHS), Yaoundé, Cameroon
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| |
Collapse
|
4
|
Boyce KJ. The Microevolution of Antifungal Drug Resistance in Pathogenic Fungi. Microorganisms 2023; 11:2757. [PMID: 38004768 PMCID: PMC10673521 DOI: 10.3390/microorganisms11112757] [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: 10/11/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023] Open
Abstract
The mortality rates of invasive fungal infections remain high because of the limited number of antifungal drugs available and antifungal drug resistance, which can rapidly evolve during treatment. Mutations in key resistance genes such as ERG11 were postulated to be the predominant cause of antifungal drug resistance in the clinic. However, recent advances in whole genome sequencing have revealed that there are multiple mechanisms leading to the microevolution of resistance. In many fungal species, resistance can emerge through ERG11-independent mechanisms and through the accumulation of mutations in many genes to generate a polygenic resistance phenotype. In addition, genome sequencing has revealed that full or partial aneuploidy commonly occurs in clinical or microevolved in vitro isolates to confer antifungal resistance. This review will provide an overview of the mutations known to be selected during the adaptive microevolution of antifungal drug resistance and focus on how recent advances in genome sequencing technology have enhanced our understanding of this process.
Collapse
Affiliation(s)
- Kylie J Boyce
- School of Science, RMIT University, Melbourne, VIC 3085, Australia
| |
Collapse
|
5
|
Selmecki A. Recurrent copy number variations in the human fungal pathogen Candida parapsilosis. mBio 2023; 14:e0071323. [PMID: 37787545 PMCID: PMC10653803 DOI: 10.1128/mbio.00713-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023] Open
Abstract
Candida parapsilosis is an opportunistic fungal pathogen with increasing incidence in hospital settings worldwide; however, we lack a comprehensive understanding of the mechanisms promoting its virulence and drug resistance. Bergin et al. systematically quantify the frequency and effect of copy number variation (CNV) across 170 diverse clinical and environmental isolates of C. parapsilosis (Bergin SA, Zhao F, Ryan AP, Müller CA, Nieduszynski CA, Zhai B, Rolling T, Hohl TM, Morio F, Scully J, Wolfe KH, Butler G, 2022, mBio, https://doi.org/10.1128/mbio.01777-22). Using a combination of both short- and long-read whole genome sequencing techniques, they determine the structure and copy number of two CNVs that arose recurrently throughout the evolution of these isolates. Each CNV predominantly amplifies one coding sequence (ARR3 or RTA3); however, the amplitude and recombination breakpoints are variable across the isolates. Amplification of RTA3 correlates with drug resistance and deletion causes drug susceptibility. This study highlights the need for further research into the mechanisms and dynamics of CNV formation and the impact of these CNVs on virulence and drug resistance across diverse fungal pathogens.
Collapse
Affiliation(s)
- Anna Selmecki
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Tshekiso K, Loeto D, Muzila M, Seetswane E, Kenosi K, Jongman M. Prevalence, molecular and phenotypic profiles of arboreal associated Cryptococcus neoformans in Botswana. Fungal Biol 2023; 127:1129-1135. [PMID: 37495303 DOI: 10.1016/j.funbio.2023.06.008] [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: 12/14/2022] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/28/2023]
Abstract
Mopane tree (Colophospermum mopane) is one of the main ecological niches of Cryptococcus neoformans, an opportunistic fungal pathogen that causes cryptococcosis primarily on immunocompromised hosts after inhalation of basidiospores from the environment. Hence, we investigated the prevalence, and phenotypically (antifungal resistance and biofilm formation capacity) and genotypically (mating type and genetic structure) characterized C. neoformans isolated from C. mopane, Acacia tortilis, Adansonia digitata and Ziziphus mucronata in Botswana. We report 7.1% and 2.9% prevalence of C. neoformans in C. mopane and other trees, respectively. All tested C. neoformans isolates were determined to be non-WT to fluconazole. Most isolates (65%) of C. neoformans isolates were biofilm producers. Mating type determination revealed a higher proportion of the globally rare MATa allele (53%) and a single MATα/MATa hybrid. The observed genotypeswere VNI (71%), VNB (23%) and VNB/VNB hybrids (6%). Native trees other than C. mopane are alternative ecological niches of antifungal resistant C. neoformans, and this represents a serious public health concern,and this represents a serious public health concern, especially for high-risk populations. Prevalence of C. neoformans on native trees and the observed emergence of hybrids (evidence of sexual recombination) highlight the need for increased surveillance and risk assessment within a One Health paradigm.
Collapse
Affiliation(s)
- Kgomotso Tshekiso
- Department of Biological Sciences, Faculty of Science, University of Botswana, Private Bag 0022, Gaborone, Botswana
| | - Daniel Loeto
- Department of Biological Sciences, Faculty of Science, University of Botswana, Private Bag 0022, Gaborone, Botswana
| | - Mbaki Muzila
- Department of Biological Sciences, Faculty of Science, University of Botswana, Private Bag 0022, Gaborone, Botswana
| | - Eunicah Seetswane
- Department of Biological Sciences, Faculty of Science, University of Botswana, Private Bag 0022, Gaborone, Botswana
| | - Kebabonye Kenosi
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Private Bag 0022, Gaborone, Botswana
| | - Mosimanegape Jongman
- Department of Biological Sciences, Faculty of Science, University of Botswana, Private Bag 0022, Gaborone, Botswana.
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Zhao Y, Ye L, Zhao F, Zhang L, Lu Z, Chu T, Wang S, Liu Z, Sun Y, Chen M, Liao G, Ding C, Xu Y, Liao W, Wang L. Cryptococcus neoformans, a global threat to human health. Infect Dis Poverty 2023; 12:20. [PMID: 36932414 PMCID: PMC10020775 DOI: 10.1186/s40249-023-01073-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND Emerging fungal pathogens pose important threats to global public health. The World Health Organization has responded to the rising threat of traditionally neglected fungal infections by developing a Fungal Priority Pathogens List (FPPL). Taking the highest-ranked fungal pathogen in the FPPL, Cryptococcus neoformans, as a paradigm, we review progress made over the past two decades on its global burden, its clinical manifestation and management of cryptococcal infection, and its antifungal resistance. The purpose of this review is to drive research efforts to improve future diagnoses, therapies, and interventions associated with fungal infections. METHODS We first reviewed trends in the global burden of HIV-associated cryptococcal infection, mainly based on a series of systematic studies. We next conducted scoping reviews in accordance with the guidelines described in the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews using PubMed and ScienceDirect with the keyword Cryptococcus neoformans to identify case reports of cryptococcal infections published since 2000. We then reviewed recent updates on the diagnosis and antifungal treatment of cryptococcal infections. Finally, we summarized knowledge regarding the resistance and tolerance of C. neoformans to approved antifungal drugs. RESULTS There has been a general reduction in the estimated global burden of HIV-associated cryptococcal meningitis since 2009, probably due to improvements in highly active antiretroviral therapies. However, cryptococcal meningitis still accounts for 19% of AIDS-related deaths annually. The incidences of CM in Europe and North America and the Latin America region have increased by approximately two-fold since 2009, while other regions showed either reduced or stable numbers of cases. Unfortunately, diagnostic and treatment options for cryptococcal infections are limited, and emerging antifungal resistance exacerbates the public health burden. CONCLUSION The rising threat of C. neoformans is compounded by accumulating evidence for its ability to infect immunocompetent individuals and the emergence of antifungal-resistant variants. Emphasis should be placed on further understanding the mechanisms of pathogenicity and of antifungal resistance and tolerance. The development of novel management strategies through the identification of new drug targets and the discovery and optimization of new and existing diagnostics and therapeutics are key to reducing the health burden.
Collapse
Affiliation(s)
- Youbao Zhao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, 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, 100039, China
| | - Fujie Zhao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, 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, 100039, China
| | - Zhenguo Lu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, China
| | - Tianxin Chu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, China
| | - Siyu Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, China
| | - Zhanxiang Liu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, China
| | - Yukai Sun
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, Henan, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Shanghai, 200003, China
| | - Guojian Liao
- The Medical Research Institute, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Chen Ding
- College of Life and Health Sciences, Northeastern University, Shenyang, 110819, Liaoning, China
| | - Yingchun Xu
- Department of Laboratory Medicine, and Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Wanqing Liao
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Shanghai, 200003, 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, 100039, China.
| |
Collapse
|
11
|
Jackson KM, Ding M, Nielsen K. Importance of Clinical Isolates in Cryptococcus neoformans Research. J Fungi (Basel) 2023; 9:364. [PMID: 36983532 PMCID: PMC10056780 DOI: 10.3390/jof9030364] [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: 02/20/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023] Open
Abstract
The human pathogenic fungus Cryptococcus neoformans is a global health concern. Previous research in the field has focused on studies using reference strains to identify virulence factors, generate mutant libraries, define genomic structures, and perform functional studies. In this review, we discuss the benefits and drawbacks of using reference strains to study C. neoformans, describe how the study of clinical isolates has expanded our understanding of pathogenesis, and highlight how studies using clinical isolates can further develop our understanding of the host-pathogen interaction during C. neoformans infection.
Collapse
Affiliation(s)
| | | | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
12
|
Deng H, Song J, Huang Y, Yang C, Zang X, Zhou Y, Li H, Dai B, Xue X. Combating increased antifungal drug resistance in Cryptococcus, what should we do in the future? Acta Biochim Biophys Sin (Shanghai) 2023; 55:540-547. [PMID: 36815374 DOI: 10.3724/abbs.2023011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Few therapeutic drugs and increased drug resistance have aggravated the current treatment difficulties of Cryptococcus in recent years. To better understand the antifungal drug resistance mechanism and treatment strategy of cryptococcosis. In this review, by combining the fundamental features of Cryptococcus reproduction leading to changes in its genome, we review recent research into the mechanism of four current anti-cryptococcal agents, coupled with new therapeutic strategies and the application of advanced technologies WGS and CRISPR-Cas9 in this field, hoping to provide a broad idea for the future clinical therapy of cryptococcosis.
Collapse
Affiliation(s)
- Hengyu Deng
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Jialin Song
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Yemei Huang
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Chen Yang
- Department of Laboratory Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Xuelei Zang
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Yangyu Zhou
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Hongli Li
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Bin Dai
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Xinying Xue
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China.,Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| |
Collapse
|
13
|
Hoy MJ, Heitman J. Drug Target Elucidation Through Isolation and Analysis of Drug-Resistant Mutants in Cryptococcus neoformans. Methods Mol Biol 2023; 2658:127-143. [PMID: 37024699 PMCID: PMC10602406 DOI: 10.1007/978-1-0716-3155-3_9] [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] [Indexed: 04/08/2023]
Abstract
Drug target identification is an essential component to antifungal drug development. Many methods, including large chemical library screening, natural product screening, and drug repurposing efforts, can identify compounds with favorable in vitro antifungal activity. However, these approaches will often identify compounds with no known mechanism of action. Herein, we describe a method utilizing the human fungal pathogen Cryptococcus neoformans to identify antifungal drug targets through the isolation of spontaneous resistant mutants, antifungal testing, whole-genome sequencing, and variant analysis.
Collapse
Affiliation(s)
- Michael J Hoy
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
| |
Collapse
|
14
|
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: 9] [Impact Index Per Article: 4.5] [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.
Collapse
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
| |
Collapse
|
15
|
Fisher MC, Alastruey-Izquierdo A, Berman J, Bicanic T, Bignell EM, Bowyer P, Bromley M, Brüggemann R, Garber G, Cornely OA, Gurr SJ, Harrison TS, Kuijper E, Rhodes J, Sheppard DC, Warris A, White PL, Xu J, Zwaan B, Verweij PE. Tackling the emerging threat of antifungal resistance to human health. Nat Rev Microbiol 2022; 20:557-571. [PMID: 35352028 PMCID: PMC8962932 DOI: 10.1038/s41579-022-00720-1] [Citation(s) in RCA: 297] [Impact Index Per Article: 148.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2022] [Indexed: 12/12/2022]
Abstract
Invasive fungal infections pose an important threat to public health and are an under-recognized component of antimicrobial resistance, an emerging crisis worldwide. Across a period of profound global environmental change and expanding at-risk populations, human-infecting pathogenic fungi are evolving resistance to all licensed systemic antifungal drugs. In this Review, we highlight the main mechanisms of antifungal resistance and explore the similarities and differences between bacterial and fungal resistance to antimicrobial control. We discuss the research and innovation topics that are needed for risk reduction strategies aimed at minimizing the emergence of resistance in pathogenic fungi. These topics include links between the environment and One Health, surveillance, diagnostics, routes of transmission, novel therapeutics and methods to mitigate hotspots for fungal adaptation. We emphasize the global efforts required to steward our existing antifungal armamentarium, and to direct the research and development of future therapies and interventions.
Collapse
Affiliation(s)
- Matthew C Fisher
- MRC Centre for Global Infectious Disease Outbreak Analysis, Imperial College London, London, UK.
| | - Ana Alastruey-Izquierdo
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Judith Berman
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
| | - Tihana Bicanic
- Institute of Infection and Immunity, St George's University London, London, UK
| | - Elaine M Bignell
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Paul Bowyer
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Michael Bromley
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Roger Brüggemann
- Department of Pharmacy, Radboudumc Institute for Health Sciences and Radboudumc - CWZ Centre of Expertise for Mycology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Gary Garber
- Department of Medicine and the School of Public Health and Epidemiology, University of Ottawa, Ottawa, Ontario, Canada
| | - Oliver A Cornely
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
| | | | - Thomas S Harrison
- Institute of Infection and Immunity, St George's University London, London, UK
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Ed Kuijper
- Centre for Infectious Diseases Research, Diagnostics and Laboratory Surveillance, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Johanna Rhodes
- MRC Centre for Global Infectious Disease Outbreak Analysis, Imperial College London, London, UK
| | - Donald C Sheppard
- Infectious Disease in Global Health Program and McGill Interdisciplinary Initiative in Infection and Immunity, McGill University Health Centre, Montreal, Québec, Canada
| | - Adilia Warris
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - P Lewis White
- Public Health Wales Mycology Reference Laboratory, University Hospital of Wales, Cardiff, UK
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Bas Zwaan
- Department of Plant Science, Laboratory of Genetics, Wageningen University & Research, Wageningen, Netherlands
| | - Paul E Verweij
- Centre for Infectious Diseases Research, Diagnostics and Laboratory Surveillance, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands.
- Department of Medical Microbiology and Radboudumc - CWZ Centre of Expertise for Mycology, Radboud University Medical Centre, Nijmegen, Netherlands.
| |
Collapse
|
16
|
Drug Resistance and Evolvability in an Emerging Human Fungal Pathogen. mBio 2022; 13:e0187622. [PMID: 35980032 PMCID: PMC9600676 DOI: 10.1128/mbio.01876-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over the past decade, Candida auris has emerged as a highly transmissible human fungal pathogen. Because of its ability to transmit between patients in hospitals and its ability to rapidly develop drug resistance, C. auris presents unique challenges. However, at a genetic and genomic level we still understand relatively little about how drug resistance develops in this pathogen. Burrack et al. use experimental evolution and whole-genome sequencing to identify mutations correlated with fluconazole resistance in C. auris. They identify interesting genomic features, including highly plastic subtelomeric regions and whole chromosomal and segmental aneuploidies. Excitingly, they also identify the first example of a hypermutator strain in C. auris. In comparison with the model human fungal pathogen Candida albicans, C. auris is more likely to undergo mutation and less likely to undergo copy number variation in response to drug selection, which may be linked to differences in base ploidy level.
Collapse
|
17
|
Genomic Diversity across Candida auris Clinical Isolates Shapes Rapid Development of Antifungal Resistance
In Vitro
and
In Vivo. mBio 2022; 13:e0084222. [PMID: 35862787 PMCID: PMC9426540 DOI: 10.1128/mbio.00842-22] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Antifungal drug resistance and tolerance pose a serious threat to global public health. In the human fungal pathogen, Candida auris, resistance to triazole, polyene, and echinocandin antifungals is rising, resulting in multidrug resistant isolates. Here, we use genome analysis and in vitro evolution of 17 new clinical isolates of C. auris from clades I and IV to determine how quickly resistance mutations arise, the stability of resistance in the absence of drug, and the impact of genetic background on evolutionary trajectories. We evolved each isolate in the absence of drug as well as in low and high concentrations of fluconazole. In just three passages, we observed genomic and phenotypic changes including karyotype alterations, aneuploidy, acquisition of point mutations, and increases in MIC values within the populations. Fluconazole resistance was stable in the absence of drug, indicating little to no fitness cost associated with resistance. Importantly, two isolates substantially increased resistance to ≥256 μg/mL fluconazole. Multiple evolutionary pathways and mutations associated with increased fluconazole resistance occurred simultaneously within the same population. Strikingly, the subtelomeric regions of C. auris were highly dynamic as deletion of multiple genes near the subtelomeres occurred during the three passages in several populations. Finally, we discovered a mutator phenotype in a clinical isolate of C. auris. This isolate had elevated mutation rates compared to other isolates and acquired substantial resistance during evolution in vitro and in vivo supporting that the genetic background of clinical isolates can have a significant effect on evolutionary potential.
Collapse
|
18
|
Evolutionary Significance of Fungal Hypermutators: Lessons Learned from Clinical Strains and Implications for Fungal Plant Pathogens. mSphere 2022; 7:e0008722. [PMID: 35638358 PMCID: PMC9241500 DOI: 10.1128/msphere.00087-22] [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
Rapid evolution of fungal pathogens poses a serious threat to medicine and agriculture. The mutation rate determines the pace of evolution of a fungal pathogen. Hypermutator fungal strains have an elevated mutation rate owing to certain defects such as those in the DNA mismatch repair system. Studies in Saccharomyces cerevisiae show that hypermutators expedite evolution by generating beneficial alleles at a faster pace than the wild-type strains. However, an accumulation of deleterious alleles in a hypermutator may reduce its fitness. The balance between fitness cost and mutation benefit determines the prevalence of hypermutators in a population. This balance is affected by a complex interaction of ploidy, mode of reproduction, population size, and recent population history. Studies in human fungal pathogens like Aspergillus fumigatus, Candida albicans, Candida glabrata, Cryptococcus deuterogattii, and Cryptococcus neoformans have highlighted the importance of hypermutators in host adaptation and development of antifungal resistance. However, a critical examination of hypermutator biology, experimental evolution studies, and epidemiological studies suggests that hypermutators may impact evolutionary investigations. This review aims to integrate the knowledge about biology, experimental evolution, and dynamics of fungal hypermutators to critically examine the evolutionary role of hypermutators in fungal pathogen populations and project implications of hypermutators in the evolution of fungal plant pathogen populations. Understanding the factors determining the emergence and evolution of fungal hypermutators can open a novel avenue of managing rapidly evolving fungal pathogens in medicine and agriculture.
Collapse
|
19
|
Mutators Enhance Adaptive Micro-Evolution in Pathogenic Microbes. Microorganisms 2022; 10:microorganisms10020442. [PMID: 35208897 PMCID: PMC8875331 DOI: 10.3390/microorganisms10020442] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/07/2022] [Accepted: 02/10/2022] [Indexed: 02/04/2023] Open
Abstract
Adaptation to the changing environmental conditions experienced within a host requires genetic diversity within a microbial population. Genetic diversity arises from mutations which occur due to DNA damage from exposure to exogenous environmental stresses or generated endogenously through respiration or DNA replication errors. As mutations can be deleterious, a delicate balance must be obtained between generating enough mutations for micro-evolution to occur while maintaining fitness and genomic integrity. Pathogenic microorganisms can actively modify their mutation rate to enhance adaptive micro-evolution by increasing expression of error-prone DNA polymerases or by mutating or decreasing expression of genes required for DNA repair. Strains which exhibit an elevated mutation rate are termed mutators. Mutators are found in varying prevalence in clinical populations where large-effect beneficial mutations enhance survival and are predominately caused by defects in the DNA mismatch repair (MMR) pathway. Mutators can facilitate the emergence of antibiotic resistance, allow phenotypic modifications to prevent recognition and destruction by the host immune system and enable switching to metabolic and cellular morphologies better able to survive in the given environment. This review will focus on recent advances in understanding the phenotypic and genotypic changes occurring in MMR mutators in both prokaryotic and eukaryotic pathogens.
Collapse
|
20
|
Birkenfeld ZM, Dittel N, Harrer T, Stephan C, Kiderlen AF, Rickerts V. Phenotypic Diversity of C. neoformans var. neoformans Clinical Isolates from Localized and Disseminated Infections. Microorganisms 2022; 10:microorganisms10020321. [PMID: 35208777 PMCID: PMC8878387 DOI: 10.3390/microorganisms10020321] [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] [Received: 01/04/2022] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 12/02/2022] Open
Abstract
Cryptococcus neoformans var. neoformans is the second most prevalent agent of cryptococcosis in central Europe. Infections mostly present with localized skin and disseminated infections. Previous studies did not find these presentations to be determined by the fungal genotype as detected by multilocus sequence typing (MLST). However, phenotypic fungal traits may impact clinical presentation. Here, we studied the growth and virulence factors of C. neoformans var. neoformans isolates from disseminated and localized infections and an environmental isolate. We used coincubation with Acanthamoeba castellanii and the Galleria mellonella infection model to identify phenotypic characteristics potentially associated with clinical presentation. Clinical isolates of C. neoformans var. neoformans present a substantial phenotypic variability. Median survival of G. mellonella varied between 6 and 14 days. C. neoformans var. neoformans isolates from disseminated infections showed stronger melanization and larger capsules. They demonstrated superior uptake into an amoeba and increased cytotoxicity for the amoeba. Differences of strains from localized and disseminated infections in coincubation with amoeba are in line with the importance of phagocytes in the pathogenesis of disseminated cryptococcosis. Phenotypic traits and non-vertebrate infection models may help understand the virulence potential of C. neoformans var. neoformans isolates.
Collapse
Affiliation(s)
- Zena M. Birkenfeld
- Department of Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany; (Z.M.B.); (N.D.); (A.F.K.)
| | - Nikita Dittel
- Department of Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany; (Z.M.B.); (N.D.); (A.F.K.)
| | - Thomas Harrer
- Medizinische Klinik 3, Sektion Klinische Infektiologie und Immundefizienz, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, 91054 Erlangen, Germany;
| | - Christoph Stephan
- Medizinische Klinik 2, Infektiologie und Therapie der HIV Infektion, Universitätsklinikum Frankfurt, 60596 Frankfurt am Main, Germany;
| | - Albrecht F. Kiderlen
- Department of Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany; (Z.M.B.); (N.D.); (A.F.K.)
| | - Volker Rickerts
- Department of Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany; (Z.M.B.); (N.D.); (A.F.K.)
- Correspondence:
| |
Collapse
|
21
|
Albehaijani SHI, Macreadie I, Morrissey CO, Boyce KJ. OUP accepted manuscript. JAC Antimicrob Resist 2022; 4:dlac033. [PMID: 35402912 PMCID: PMC8986524 DOI: 10.1093/jacamr/dlac033] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/08/2022] [Indexed: 12/02/2022] Open
Abstract
Background Fungal infections are common life-threatening diseases amongst immunodeficient individuals. Invasive fungal disease is commonly treated with an azole antifungal agent, resulting in selection pressure and the emergence of drug resistance. Antifungal resistance is associated with higher mortality rates and treatment failure, making the current clinical management of fungal disease very challenging. Clinical isolates from a variety of fungi have been shown to contain mutations in the MSH2 gene, encoding a component of the DNA mismatch repair pathway. Mutation of MSH2 results in an elevated mutation rate that can increase the opportunity for selectively advantageous mutations to occur, accelerating the development of antifungal resistance. Objectives To characterize the molecular mechanisms causing the microevolutionary emergence of antifungal resistance in msh2 mismatch repair mutants of Cryptococcus neoformans. Methods The mechanisms resulting in the emergence of antifungal resistance were investigated using WGS, characterization of deletion mutants and measuring ploidy changes. Results The genomes of resistant strains did not possess mutations in ERG11 or other genes of the ergosterol biosynthesis pathway. Antifungal resistance was due to small contributions from mutations in many genes. MSH2 does not directly affect ploidy changes. Conclusions This study provides evidence that resistance to fluconazole can evolve independently of ERG11 mutations. A common microevolutionary route to the emergence of antifungal resistance involves the accumulation of mutations that alter stress signalling, cellular efflux, membrane trafficking, epigenetic modification and aneuploidy. This complex pattern of microevolution highlights the significant challenges posed both to diagnosis and treatment of drug-resistant fungal pathogens.
Collapse
Affiliation(s)
| | - Ian Macreadie
- School of Science, RMIT University, Melbourne, VIC, Australia
| | - C. Orla Morrissey
- Department of Infectious Diseases, Alfred Health and Monash University, Melbourne, VIC, Australia
| | - Kylie J. Boyce
- School of Science, RMIT University, Melbourne, VIC, Australia
- Corresponding author. E-mail:
| |
Collapse
|
22
|
Emergence and evolution of virulence in human pathogenic fungi. Trends Microbiol 2022; 30:693-704. [DOI: 10.1016/j.tim.2021.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 12/23/2022]
|
23
|
Reis RS, Bonna ICF, Antonio IMDS, Pereira SA, do Nascimento CRS, Ferraris FK, Brito-Santos F, Ferreira Gremião ID, Trilles L. Cryptococcus neoformans VNII as the Main Cause of Cryptococcosis in Domestic Cats from Rio de Janeiro, Brazil. J Fungi (Basel) 2021; 7:jof7110980. [PMID: 34829267 PMCID: PMC8621350 DOI: 10.3390/jof7110980] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
Cryptococcosis is a systemic fungal disease acquired from contaminated environments with propagules of the basidiomycetous yeasts of the Cryptococcus neoformans and C. gattii species complexes. The C. neoformans species complex classically comprises four major molecular types (VNI, VNII, VNIII, and VNIV), and the C. gattii species complex comprises another four (VGI, VGII, VGIII, and VGIV) and the newly identified molecular type VGV. These major molecular types differ in their epidemiological and ecological features, clinical presentations, and therapeutic outcomes. Generally, the most common isolated types are VNI, VGI, and VGII. The epidemiological profile of cryptococcosis in domestic cats is poorly studied and cats can be the sentinels for human infections. Therefore, the present study aimed to determine the molecular characterization of Cryptococcus spp. isolated from domestic cats and their dwellings in the metropolitan area of Rio de Janeiro, Brazil. A total of 36 Cryptococcus spp. strains, both clinical and environmental, from 19 cats were subtyped using multilocus sequence typing (MLST). The ploidy was identified using flow cytometry and the mating type was determined through amplification with specific pheromone primers. All strains were mating type alpha and 6/36 were diploid (all VNII). Most isolates (63.88%) were identified as VNII, a rare molecular type, leading to the consideration that this genotype is more likely related to skin lesions, since there was a high percentage (68.75%) of cats with skin lesions, which is also considered rare. Further studies regarding the molecular epidemiology of cryptococcosis in felines are still needed to clarify the reason for the large proportion of the rare molecular type VNII causing infections in cats.
Collapse
Affiliation(s)
- Rosani Santos Reis
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro 21040-900, Brazil; (R.S.R.); (I.C.F.B.); (F.B.-S.)
| | - Isabel Cristina Fábregas Bonna
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro 21040-900, Brazil; (R.S.R.); (I.C.F.B.); (F.B.-S.)
| | - Isabela Maria da Silva Antonio
- Laboratory of Clinical Research on Dermatozoonoses in Domestic Animals (Lapclin-Dermzoo)/INI/Fiocruz, Rio de Janeiro 21040-900, Brazil; (I.M.d.S.A.); (S.A.P.); (I.D.F.G.)
| | - Sandro Antonio Pereira
- Laboratory of Clinical Research on Dermatozoonoses in Domestic Animals (Lapclin-Dermzoo)/INI/Fiocruz, Rio de Janeiro 21040-900, Brazil; (I.M.d.S.A.); (S.A.P.); (I.D.F.G.)
| | | | - Fausto Klabund Ferraris
- Pharmacology Laboratory/INCQS/Fiocruz. Av. Brasil, 4365, Manguinhos, Rio de Janeiro 21040-900, Brazil;
| | - Fábio Brito-Santos
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro 21040-900, Brazil; (R.S.R.); (I.C.F.B.); (F.B.-S.)
| | - Isabella Dib Ferreira Gremião
- Laboratory of Clinical Research on Dermatozoonoses in Domestic Animals (Lapclin-Dermzoo)/INI/Fiocruz, Rio de Janeiro 21040-900, Brazil; (I.M.d.S.A.); (S.A.P.); (I.D.F.G.)
| | - Luciana Trilles
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro 21040-900, Brazil; (R.S.R.); (I.C.F.B.); (F.B.-S.)
- Correspondence:
| |
Collapse
|
24
|
Abstract
Cryptococcus neoformans is a major human central nervous system (CNS) fungal pathogen causing considerable morbidity and mortality. In this study, we provide the widest view to date of the yeast transcriptome directly from the human subarachnoid space and within cerebrospinal fluid (CSF). We captured yeast transcriptomes from C. neoformans of various genotypes in 31 patients with cryptococcal meningoencephalitis as well as several Cryptococcus gattii infections. Using transcriptome sequencing (RNA-seq) analyses, we compared the in vivo yeast transcriptomes to those from other environmental conditions, including in vitro growth on nutritious media or artificial CSF as well as samples collected from rabbit CSF at two time points. We ranked gene expressions and identified genetic patterns and networks across these diverse isolates that reveal an emphasis on carbon metabolism, fatty acid synthesis, transport, cell wall structure, and stress-related gene functions during growth in CSF. The most highly expressed yeast genes in human CSF included those known to be associated with survival or virulence and highlighted several genes encoding hypothetical proteins. From that group, a gene encoding the CMP1 putative glycoprotein (CNAG_06000) was selected for functional studies. This gene was found to impact the virulence of Cryptococcus in both mice and the CNS rabbit model, in agreement with a recent study also showing a role in virulence. This transcriptional analysis strategy provides a view of regulated yeast genes across genetic backgrounds important for human CNS infection and a relevant resource for the study of cryptococcal genes, pathways, and networks linked to human disease.
Collapse
|
25
|
Phillips MA, Steenwyk JL, Shen XX, Rokas A. Examination of Gene Loss in the DNA Mismatch Repair Pathway and Its Mutational Consequences in a Fungal Phylum. Genome Biol Evol 2021; 13:evab219. [PMID: 34554246 PMCID: PMC8597960 DOI: 10.1093/gbe/evab219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2021] [Indexed: 12/12/2022] Open
Abstract
The DNA mismatch repair (MMR) pathway corrects mismatched bases produced during DNA replication and is highly conserved across the tree of life, reflecting its fundamental importance for genome integrity. Loss of function in one or a few MMR genes can lead to increased mutation rates and microsatellite instability, as seen in some human cancers. Although loss of MMR genes has been documented in the context of human disease and in hypermutant strains of pathogens, examples of entire species and species lineages that have experienced substantial MMR gene loss are lacking. We examined the genomes of 1,107 species in the fungal phylum Ascomycota for the presence of 52 genes known to be involved in the MMR pathway of fungi. We found that the median ascomycete genome contained 49/52 MMR genes. In contrast, four closely related species of obligate plant parasites from the powdery mildew genera Erysiphe and Blumeria, have lost between five and 21 MMR genes, including MLH3, EXO1, and DPB11. The lost genes span MMR functions, include genes that are conserved in all other ascomycetes, and loss of function of any of these genes alone has been previously linked to increased mutation rate. Consistent with the hypothesis that loss of these genes impairs MMR pathway function, we found that powdery mildew genomes with higher levels of MMR gene loss exhibit increased numbers of mononucleotide runs, longer microsatellites, accelerated sequence evolution, elevated mutational bias in the A|T direction, and decreased GC content. These results identify a striking example of macroevolutionary loss of multiple MMR pathway genes in a eukaryotic lineage, even though the mutational outcomes of these losses appear to resemble those associated with detrimental MMR dysfunction in other organisms.
Collapse
Affiliation(s)
| | | | - Xing-Xing Shen
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, USA
| |
Collapse
|
26
|
Brackin AP, Hemmings SJ, Fisher MC, Rhodes J. Fungal Genomics in Respiratory Medicine: What, How and When? Mycopathologia 2021; 186:589-608. [PMID: 34490551 PMCID: PMC8421194 DOI: 10.1007/s11046-021-00573-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/14/2021] [Indexed: 12/20/2022]
Abstract
Respiratory infections caused by fungal pathogens present a growing global health concern and are a major cause of death in immunocompromised patients. Worryingly, coronavirus disease-19 (COVID-19) resulting in acute respiratory distress syndrome has been shown to predispose some patients to airborne fungal co-infections. These include secondary pulmonary aspergillosis and mucormycosis. Aspergillosis is most commonly caused by the fungal pathogen Aspergillus fumigatus and primarily treated using the triazole drug group, however in recent years, this fungus has been rapidly gaining resistance against these antifungals. This is of serious clinical concern as multi-azole resistant forms of aspergillosis have a higher risk of mortality when compared against azole-susceptible infections. With the increasing numbers of COVID-19 and other classes of immunocompromised patients, early diagnosis of fungal infections is critical to ensuring patient survival. However, time-limited diagnosis is difficult to achieve with current culture-based methods. Advances within fungal genomics have enabled molecular diagnostic methods to become a fast, reproducible, and cost-effective alternative for diagnosis of respiratory fungal pathogens and detection of antifungal resistance. Here, we describe what techniques are currently available within molecular diagnostics, how they work and when they have been used.
Collapse
Affiliation(s)
- Amelie P Brackin
- MRC Centre for Global Disease Analysis, Imperial College London, London, UK
| | - Sam J Hemmings
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Johanna Rhodes
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| |
Collapse
|
27
|
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.
Collapse
|
28
|
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.
Collapse
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
| |
Collapse
|
29
|
Maufrais C, de Oliveira L, Bastos RW, Moyrand F, Reis FCG, Valero C, Gimenez B, Josefowicz LJ, Goldman GH, Rodrigues ML, Janbon G. Population genomic analysis of Cryptococcus Brazilian isolates reveals an African type subclade distribution. G3 (BETHESDA, MD.) 2021; 11:jkab107. [PMID: 33822048 PMCID: PMC8495746 DOI: 10.1093/g3journal/jkab107] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/29/2021] [Indexed: 12/22/2022]
Abstract
The genomes of a large number of Cryptococcus neoformans isolates have been sequenced and analyzed in recent years. These genomes have been used to understand the global population structure of this opportunistic pathogen. However, only a small number of South American isolates have been considered in these studies, and the population structure of C. neoformans in this part of the world remains elusive. Here, we analyzed the genomic sequences of 53 Brazilian Cryptococcus isolates and deciphered the C. neoformans population structure in this country. Our data reveal an African-like structure that suggested repeated intercontinental transports from Africa to South America. We also identified a mutator phenotype in one VNBII Brazilian isolate, exemplifying how fast-evolving isolates can shape the Cryptococcus population structure. Finally, phenotypic analyses revealed wide diversity but not lineage specificity in the expression of classical virulence traits within the set of isolates.
Collapse
Affiliation(s)
- Corinne Maufrais
- Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Institut Pasteur, F-75015 Paris, France
- Institut Pasteur, HUB Bioinformatique et Biostatistique, C3BI, USR 3756 IP CNRS, F-75015 Paris, France
| | - Luciana de Oliveira
- Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Institut Pasteur, F-75015 Paris, France
| | - Rafael W Bastos
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 Ribeirão Preto, Brazil
| | - Frédérique Moyrand
- Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Institut Pasteur, F-75015 Paris, France
| | - Flavia C G Reis
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), 81310-020 Curitiba, Brazil
- Centro de Desenvolvimento Tecnologico em Saude (CDTS-Fiocruz), 21040-361 Rio de Janeiro, Brazil
| | - Clara Valero
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 Ribeirão Preto, Brazil
| | - Bianca Gimenez
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), 81310-020 Curitiba, Brazil
| | - Luisa J Josefowicz
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), 81310-020 Curitiba, Brazil
| | - Gustavo H Goldman
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 Ribeirão Preto, Brazil
| | - Marcio L Rodrigues
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), 81310-020 Curitiba, Brazil
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Guilhem Janbon
- Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Institut Pasteur, F-75015 Paris, France
| |
Collapse
|
30
|
Hong N, Chen M, Xu J. Molecular Markers Reveal Epidemiological Patterns and Evolutionary Histories of the Human Pathogenic Cryptococcus. Front Cell Infect Microbiol 2021; 11:683670. [PMID: 34026667 PMCID: PMC8134695 DOI: 10.3389/fcimb.2021.683670] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 04/22/2021] [Indexed: 01/02/2023] Open
Abstract
The human pathogenic Cryptococcus species are the main agents of fungal meningitis in humans and the causes of other diseases collectively called cryptococcosis. There are at least eight evolutionary divergent lineages among these agents, with different lineages showing different geographic and/or ecological distributions. In this review, we describe the main strain typing methods that have been used to analyze the human pathogenic Cryptococcus and discuss how molecular markers derived from the various strain typing methods have impacted our understanding of not only cryptococcal epidemiology but also its evolutionary histories. These methods include serotyping, multilocus enzyme electrophoresis, electrophoretic karyotyping, random amplified polymorphic DNA, restriction fragment length polymorphism, PCR-fingerprinting, amplified fragment length polymorphism, multilocus microsatellite typing, single locus and multilocus sequence typing, matrix-assisted laser desorption/ionization time of flight mass spectrometry, and whole genome sequencing. The major findings and the advantages and disadvantages of each method are discussed. Together, while controversies remain, these strain typing methods have helped reveal (i) the broad phylogenetic pattern among these agents, (ii) the centers of origins for several lineages and their dispersal patterns, (iii) the distributions of genetic variation among geographic regions and ecological niches, (iv) recent hybridization among several lineages, and (v) specific mutations during infections within individual patients. However, significant challenges remain. Multilocus sequence typing and whole genome sequencing are emerging as the gold standards for continued strain typing and epidemiological investigations of cryptococcosis.
Collapse
Affiliation(s)
- Nan Hong
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China.,Department of Burn and Plastic Surgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
31
|
Naicker SD, Magobo RE, Maphanga TG, Firacative C, van Schalkwyk E, Monroy-Nieto J, Bowers J, Engelthaler DM, Shuping L, Meyer W, Govender NP. Genotype, Antifungal Susceptibility, and Virulence of Clinical South African Cryptococcus neoformans Strains from National Surveillance, 2005-2009. J Fungi (Basel) 2021; 7:jof7050338. [PMID: 33925754 PMCID: PMC8146981 DOI: 10.3390/jof7050338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 01/04/2023] Open
Abstract
In South Africa, Cryptococcus neoformans is the most common cause of adult meningitis. We performed multi locus sequence typing and fluconazole susceptibility testing of clinical C. neoformans isolates collected from 251 South African patients with cryptococcosis through national surveillance from 2005 to 2009. We examined the association between clinical characteristics of patients and genotype, and the effect of genotype on in-hospital mortality. We performed whole genome phylogenetic analysis of fifteen C. neoformans isolates with the molecular type VNB and tested their virulence in a Galleria mellonella model. Most isolates had the molecular type VNI (206/251, 82%), followed by VNII (25/251, 10%), VNB (15/251, 6%), and VNIV (5/251, 2%); 67 sequence types were identified. There were no differences in fluconazole minimum inhibitory concentration (MIC) values among molecular types and the majority of strains had low MIC values (MIC50 of 1 µg/mL and MIC90 of 4 µg/mL). Males were almost twice as likely of being infected with a non-VNI genotype (adjusted odds ratio [OR]: 1.65, 95% confidence interval [CI]: 0.25–10.99; p = 0.61). Compared to patients infected with a VNI genotype, those with a non-VNI genotype had a 50% reduced adjusted odds of dying in hospital (95% CI: 0.03–7.57; p = 0.62). However, for both these analyses, our estimates had wide confidence intervals spanning 1 with large p-values. Fifteen VNB strains were not as virulent in a G. mellonella larval model as the H99 reference strain. A majority of these VNB strains belonged to the VNBII clade and were very closely related by phylogenetic analysis.
Collapse
Affiliation(s)
- Serisha D. Naicker
- Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa; (R.E.M.); (T.G.M.); (E.v.S.); (L.S.); (N.P.G.)
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa
- Correspondence: ; Tel.: +27-11-555-0491
| | - Rindidzani E. Magobo
- Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa; (R.E.M.); (T.G.M.); (E.v.S.); (L.S.); (N.P.G.)
| | - Tsidiso G. Maphanga
- Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa; (R.E.M.); (T.G.M.); (E.v.S.); (L.S.); (N.P.G.)
| | - Carolina Firacative
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, 111611 Bogota, Colombia;
| | - Erika van Schalkwyk
- Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa; (R.E.M.); (T.G.M.); (E.v.S.); (L.S.); (N.P.G.)
| | - Juan Monroy-Nieto
- Pathogen and Microbiome Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (J.M.-N.); (J.B.); (D.M.E.)
| | - Jolene Bowers
- Pathogen and Microbiome Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (J.M.-N.); (J.B.); (D.M.E.)
| | - David M. Engelthaler
- Pathogen and Microbiome Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (J.M.-N.); (J.B.); (D.M.E.)
| | - Liliwe Shuping
- Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa; (R.E.M.); (T.G.M.); (E.v.S.); (L.S.); (N.P.G.)
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Center for Infectious Diseases and Microbiology, Westmead Clinical School, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia;
- Marie Bashir Institute for Emerging Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW 2006, Australia
- Westmead Institute for Medical Research, Westmead, NSW 2145, Australia
- Research and Educational Network, Westmead Hospital, Western Sydney Local Health District, Westmead, NSW 2145, Australia
| | - Nelesh P. Govender
- Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa; (R.E.M.); (T.G.M.); (E.v.S.); (L.S.); (N.P.G.)
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town 7701, South Africa
| |
Collapse
|
32
|
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: 24] [Impact Index Per Article: 8.0] [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.
Collapse
|
33
|
Abstract
Cell cycle checkpoints and DNA repair pathways contribute to maintaining genome integrity and are thought to be evolutionarily ancient and broadly conserved. For example, in the yeast Saccharomyces cerevisiae and humans, DNA damage induces activation of a checkpoint effector kinase, Rad53p (human homolog Chk2), to promote cell cycle arrest and transcription of DNA repair genes. Cell cycle checkpoints and DNA repair pathways contribute to maintaining genome integrity and are thought to be evolutionarily ancient and broadly conserved. For example, in the yeast Saccharomyces cerevisiae and humans, DNA damage induces activation of a checkpoint effector kinase, Rad53p (human homolog Chk2), to promote cell cycle arrest and transcription of DNA repair genes. However, recent studies have revealed variation in the DNA damage response networks of some fungi. For example, Shor et al. (mBio 11:e03044-20, 2020, https://doi.org/10.1128/mBio.03044-20) demonstrate that in comparison to S. cerevisiae, the fungal pathogen Candida glabrata has reduced activation of Rad53p in response to DNA damage. Consequently, some downstream targets that contribute to S. cerevisiae genome maintenance, such as DNA polymerases, are transcriptionally downregulated in C. glabrata. Downregulation of genome maintenance genes likely contributes to higher rates of mitotic failure and cell death in C. glabrata. This and other recent findings highlight evolutionary diversity in eukaryotic DNA damage responses.
Collapse
|
34
|
Hu M, Chen S. Non-Target Site Mechanisms of Fungicide Resistance in Crop Pathogens: A Review. Microorganisms 2021; 9:microorganisms9030502. [PMID: 33673517 PMCID: PMC7997439 DOI: 10.3390/microorganisms9030502] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/18/2021] [Accepted: 02/23/2021] [Indexed: 01/15/2023] Open
Abstract
The rapid emergence of resistance in plant pathogens to the limited number of chemical classes of fungicides challenges sustainability and profitability of crop production worldwide. Understanding mechanisms underlying fungicide resistance facilitates monitoring of resistant populations at large-scale, and can guide and accelerate the development of novel fungicides. A majority of modern fungicides act to disrupt a biochemical function via binding a specific target protein in the pathway. While target-site based mechanisms such as alternation and overexpression of target genes have been commonly found to confer resistance across many fungal species, it is not uncommon to encounter resistant phenotypes without altered or overexpressed target sites. However, such non-target site mechanisms are relatively understudied, due in part to the complexity of the fungal genome network. This type of resistance can oftentimes be transient and noninheritable, further hindering research efforts. In this review, we focused on crop pathogens and summarized reported mechanisms of resistance that are otherwise related to target-sites, including increased activity of efflux pumps, metabolic circumvention, detoxification, standing genetic variations, regulation of stress response pathways, and single nucleotide polymorphisms (SNPs) or mutations. In addition, novel mechanisms of drug resistance recently characterized in human pathogens are reviewed in the context of nontarget-directed resistance.
Collapse
Affiliation(s)
- Mengjun Hu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA
- Correspondence: (M.H.); (S.C.)
| | - Shuning Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (M.H.); (S.C.)
| |
Collapse
|
35
|
Treatment strategies for cryptococcal infection: challenges, advances and future outlook. Nat Rev Microbiol 2021; 19:454-466. [PMID: 33558691 PMCID: PMC7868659 DOI: 10.1038/s41579-021-00511-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 01/31/2023]
Abstract
Cryptococcus spp., in particular Cryptococcus neoformans and Cryptococcus gattii, have an enormous impact on human health worldwide. The global burden of cryptococcal meningitis is almost a quarter of a million cases and 181,000 deaths annually, with mortality rates of 100% if infections remain untreated. Despite these alarming statistics, treatment options for cryptococcosis remain limited, with only three major classes of drugs approved for clinical use. Exacerbating the public health burden is the fact that the only new class of antifungal drugs developed in decades, the echinocandins, displays negligible antifungal activity against Cryptococcus spp., and the efficacy of the remaining therapeutics is hampered by host toxicity and pathogen resistance. Here, we describe the current arsenal of antifungal agents and the treatment strategies employed to manage cryptococcal disease. We further elaborate on the recent advances in our understanding of the intrinsic and adaptive resistance mechanisms that are utilized by Cryptococcus spp. to evade therapeutic treatments. Finally, we review potential therapeutic strategies, including combination therapy, the targeting of virulence traits, impairing stress response pathways and modulating host immunity, to effectively treat infections caused by Cryptococcus spp. Overall, understanding of the mechanisms that regulate anti-cryptococcal drug resistance, coupled with advances in genomics technologies and high-throughput screening methodologies, will catalyse innovation and accelerate antifungal drug discovery.
Collapse
|
36
|
The sino-nasal warzone: transcriptomic and genomic studies on sino-nasal aspergillosis in dogs. NPJ Biofilms Microbiomes 2020; 6:51. [PMID: 33184275 PMCID: PMC7665010 DOI: 10.1038/s41522-020-00163-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/16/2020] [Indexed: 12/21/2022] Open
Abstract
We previously showed that each dog with chronic non-invasive sino-nasal aspergillosis (SNA) was infected with a single genotype of Aspergillus fumigatus. Here, we studied the transcriptome of this fungal pathogen and the canine host within the biofilm resulting from the infection. We describe here transcriptomes resulting from natural infections in animal species with A. fumigatus. The host transcriptome showed high expression of IL-8 and alarmins, uncontrolled inflammatory reaction and dysregulation of the Th17 response. The fungal transcriptome showed in particular expression of genes involved in secondary metabolites and nutrient acquisition. Single-nucleotide polymorphism analysis of fungal isolates from the biofilms showed large genetic variability and changes related with adaptation to host environmental factors. This was accompanied with large phenotypic variability in in vitro stress assays, even between isolates from the same canine patient. Our analysis provides insights in genetic and phenotypic variability of Aspergillus fumigatus in biofilms of naturally infected dogs reflecting in-host adaptation. Absence of a Th17 response and dampening of the Th1 response contributes to the formation of a chronic sino-nasal warzone.
Collapse
|
37
|
Abstract
Diversity within the fungal kingdom is evident from the wide range of morphologies fungi display as well as the various ecological roles and industrial purposes they serve. Technological advances, particularly in long-read sequencing, coupled with the increasing efficiency and decreasing costs across sequencing platforms have enabled robust characterization of fungal genomes. These sequencing efforts continue to reveal the rampant diversity in fungi at the genome level. Here, we discuss studies that have furthered our understanding of fungal genetic diversity and genomic evolution. These studies revealed the presence of both small-scale and large-scale genomic changes. In fungi, research has recently focused on many small-scale changes, such as how hypermutation and allelic transmission impact genome evolution as well as how and why a few specific genomic regions are more susceptible to rapid evolution than others. High-throughput sequencing of a diverse set of fungal genomes has also illuminated the frequency, mechanisms, and impacts of large-scale changes, which include chromosome structural variation and changes in chromosome number, such as aneuploidy, polyploidy, and the presence of supernumerary chromosomes. The studies discussed herein have provided great insight into how the architecture of the fungal genome varies within species and across the kingdom and how modern fungi may have evolved from the last common fungal ancestor and might also pave the way for understanding how genomic diversity has evolved in all domains of life.
Collapse
Affiliation(s)
- Shelby J. Priest
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| | - Vikas Yadav
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| |
Collapse
|
38
|
Bermas A, Geddes‐McAlister J. Combatting the evolution of antifungal resistance in
Cryptococcus neoformans. Mol Microbiol 2020; 114:721-734. [DOI: 10.1111/mmi.14565] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 06/09/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Arianne Bermas
- Department of Molecular and Cellular Biology University of Guelph Guelph ON Canada
| | | |
Collapse
|
39
|
Coelho C, Farrer RA. Pathogen and host genetics underpinning cryptococcal disease. ADVANCES IN GENETICS 2020; 105:1-66. [PMID: 32560785 DOI: 10.1016/bs.adgen.2020.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cryptococcosis is a severe fungal disease causing 220,000 cases of cryptococcal meningitis yearly. The etiological agents of cryptococcosis are taxonomically grouped into at least two species complexes belonging to the genus Cryptococcus. All of these yeasts are environmentally ubiquitous fungi (often found in soil, leaves and decaying wood, tree hollows, and associated with bird feces especially pigeon guano). Infection in a range of animals including humans begins following inhalation of spores or aerosolized yeasts. Recent advances provide fundamental insights into the factors from both the pathogen and its hosts which influence pathogenesis and disease. The complex interactions leading to disease in mammalian hosts have also updated from the availability of better genomic tools and datasets. In this review, we discuss recent genetic research on Cryptococcus, covering the epidemiology, ecology, and evolution of Cryptococcus pathogenic species. We also discuss the insights into the host immune response obtained from the latest genetic modified host models as well as insights from monogenic disorders in humans. Finally we highlight outstanding questions that can be answered in the near future using bioinformatics and genomic tools.
Collapse
Affiliation(s)
- Carolina Coelho
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| | - Rhys A Farrer
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom.
| |
Collapse
|
40
|
Billmyre RB, Applen Clancey S, Li LX, Doering TL, Heitman J. 5-fluorocytosine resistance is associated with hypermutation and alterations in capsule biosynthesis in Cryptococcus. Nat Commun 2020; 11:127. [PMID: 31913284 PMCID: PMC6949227 DOI: 10.1038/s41467-019-13890-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/29/2019] [Indexed: 12/27/2022] Open
Abstract
Patients infected with the fungal pathogen Cryptococcus are most effectively treated with a combination of 5-fluorocytosine (5FC) and amphotericin B. 5FC acts as a prodrug, which is converted into toxic 5-fluorouracil (5FU) upon uptake into fungal cells. However, the pathogen frequently develops resistance through unclear mechanisms. Here we show that resistance to 5FC in Cryptococcus deuterogattii is acquired more frequently in isolates with defects in DNA mismatch repair that confer an elevated mutation rate. We use whole genome sequencing of 16 independent isolates to identify mutations associated with 5FC resistance in vitro. We find mutations in known resistance genes (FUR1 and FCY2) and in a gene UXS1, previously shown to encode an enzyme that converts UDP-glucuronic acid to UDP-xylose for capsule biosynthesis, but not known to play a role in 5FC metabolism. Mutations in UXS1 lead to accumulation of UDP-glucuronic acid and alterations in nucleotide metabolism, which appear to suppress toxicity of both 5FC and its toxic derivative 5FU. The authors show that resistance to the antifungal 5-fluorocytosine in Cryptococcus deuterogattii is acquired more frequently in isolates with elevated mutation rate, and is associated with alterations in capsule biosynthesis and nucleotide metabolism.
Collapse
Affiliation(s)
- R Blake Billmyre
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.,Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO, 64110, USA
| | - Shelly Applen Clancey
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Lucy X Li
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Tamara L Doering
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
| |
Collapse
|
41
|
Boyce KJ, Cao C, Xue C, Idnurm A. A spontaneous mutation in DNA polymerase POL3 during in vitro passaging causes a hypermutator phenotype in Cryptococcus species. DNA Repair (Amst) 2019; 86:102751. [PMID: 31838381 DOI: 10.1016/j.dnarep.2019.102751] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/08/2019] [Accepted: 11/19/2019] [Indexed: 10/25/2022]
Abstract
Passaging of microbes in vitro can lead to the selection of microevolved derivatives with differing properties to their original parent strains. One well characterised instance is the phenotypic differences observed between the series of strains derived from the type strain of the human pathogenic fungus Cryptococcus neoformans. A second case was reported in the close relative Cryptococcus deneoformans, in which a well-studied isolate ATCC 24067 (52D) altered its phenotypic characteristics after in vitro passaging in different laboratories. One of these derivatives, ATCC 24067A, has decreased virulence and also exhibits a hypermutator phenotype, in which the mutation rate is increased compared to wild type. In this study, the molecular basis behind the changes in the lineage of ATCC 24067 was determined by next-generation sequencing of the parent and passaged strain genomes. This analysis resulted in the identification of a point mutation that causes a D270G amino acid substitution within the exonuclease proofreading domain of the DNA polymerase delta subunit encoded by POL3. Complementation with POL3 confirmed that this mutation is responsible for the hypermutator phenotype of this strain. Regeneration of the mutation in C. neoformans, to eliminate the additional mutations present in the ATCC 24067A genetic background, demonstrated that the hypermutator phenotype of the pol3D270G mutant causes rapid microevolution in vitro but does not result in decreased virulence. These findings indicate that mutator strains can emerge in these pathogenic fungi without conferring a fitness cost, but the subsequent rapid accumulation of mutations can be deleterious.
Collapse
Affiliation(s)
- Kylie J Boyce
- School of Science, Engineering and Health, RMIT University, Victoria, Australia.
| | - Chengjun Cao
- Public Health Research Institute, Rutgers University, Newark, New Jersey, USA
| | - Chaoyang Xue
- Public Health Research Institute, Rutgers University, Newark, New Jersey, USA
| | - Alexander Idnurm
- School of BioSciences, University of Melbourne, Victoria, Australia.
| |
Collapse
|
42
|
El-Kamand S, Papanicolaou A, Morton CO. The Use of Whole Genome and Next-Generation Sequencing in the Diagnosis of Invasive Fungal Disease. CURRENT FUNGAL INFECTION REPORTS 2019. [DOI: 10.1007/s12281-019-00363-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
43
|
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: 33] [Impact Index Per Article: 6.6] [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.
Collapse
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.
| |
Collapse
|
44
|
Abstract
The recent coverage in the mainstream media of global Candida auris outbreaks has provided the general public with an awareness of the unprecedented emergence rate of pathogenic fungi. Scientific communities need to collaboratively address this threat to public health.
Collapse
Affiliation(s)
- Johanna Rhodes
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, W2 1PG, UK.
| |
Collapse
|
45
|
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: 17] [Impact Index Per Article: 3.4] [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.
Collapse
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
| |
Collapse
|
46
|
Steenwyk JL, Opulente DA, Kominek J, Shen XX, Zhou X, Labella AL, Bradley NP, Eichman BF, Čadež N, Libkind D, DeVirgilio J, Hulfachor AB, Kurtzman CP, Hittinger CT, Rokas A. Extensive loss of cell-cycle and DNA repair genes in an ancient lineage of bipolar budding yeasts. PLoS Biol 2019; 17:e3000255. [PMID: 31112549 PMCID: PMC6528967 DOI: 10.1371/journal.pbio.3000255] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 04/18/2019] [Indexed: 02/06/2023] Open
Abstract
Cell-cycle checkpoints and DNA repair processes protect organisms from potentially lethal mutational damage. Compared to other budding yeasts in the subphylum Saccharomycotina, we noticed that a lineage in the genus Hanseniaspora exhibited very high evolutionary rates, low Guanine-Cytosine (GC) content, small genome sizes, and lower gene numbers. To better understand Hanseniaspora evolution, we analyzed 25 genomes, including 11 newly sequenced, representing 18/21 known species in the genus. Our phylogenomic analyses identify two Hanseniaspora lineages, a faster-evolving lineage (FEL), which began diversifying approximately 87 million years ago (mya), and a slower-evolving lineage (SEL), which began diversifying approximately 54 mya. Remarkably, both lineages lost genes associated with the cell cycle and genome integrity, but these losses were greater in the FEL. E.g., all species lost the cell-cycle regulator WHIskey 5 (WHI5), and the FEL lost components of the spindle checkpoint pathway (e.g., Mitotic Arrest-Deficient 1 [MAD1], Mitotic Arrest-Deficient 2 [MAD2]) and DNA-damage-checkpoint pathway (e.g., Mitosis Entry Checkpoint 3 [MEC3], RADiation sensitive 9 [RAD9]). Similarly, both lineages lost genes involved in DNA repair pathways, including the DNA glycosylase gene 3-MethylAdenine DNA Glycosylase 1 (MAG1), which is part of the base-excision repair pathway, and the DNA photolyase gene PHotoreactivation Repair deficient 1 (PHR1), which is involved in pyrimidine dimer repair. Strikingly, the FEL lost 33 additional genes, including polymerases (i.e., POLymerase 4 [POL4] and POL32) and telomere-associated genes (e.g., Repressor/activator site binding protein-Interacting Factor 1 [RIF1], Replication Factor A 3 [RFA3], Cell Division Cycle 13 [CDC13], Pbp1p Binding Protein [PBP2]). Echoing these losses, molecular evolutionary analyses reveal that, compared to the SEL, the FEL stem lineage underwent a burst of accelerated evolution, which resulted in greater mutational loads, homopolymer instabilities, and higher fractions of mutations associated with the common endogenously damaged base, 8-oxoguanine. We conclude that Hanseniaspora is an ancient lineage that has diversified and thrived, despite lacking many otherwise highly conserved cell-cycle and genome integrity genes and pathways, and may represent a novel, to our knowledge, system for studying cellular life without them.
Collapse
Affiliation(s)
- Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Dana A Opulente
- Laboratory of Genetics, Genome Center of Wisconsin, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Wisconsin, United States of America
| | - Jacek Kominek
- Laboratory of Genetics, Genome Center of Wisconsin, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Wisconsin, United States of America
| | - Xing-Xing Shen
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Xiaofan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Abigail L Labella
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Noah P Bradley
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Brandt F Eichman
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Neža Čadež
- University of Ljubljana Biotechnical Faculty, Department of Food Science and Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Diego Libkind
- Laboratorio de Microbiología Aplicada, Biotecnología y Bioinformática, Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales, Universidad Nacional del Comahue-CONICET, San Carlos de Bariloche, Río Negro, Argentina
| | - Jeremy DeVirgilio
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, Illinois, United States of America
| | - Amanda Beth Hulfachor
- Laboratory of Genetics, Genome Center of Wisconsin, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Cletus P Kurtzman
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, Illinois, United States of America
| | - Chris Todd Hittinger
- Laboratory of Genetics, Genome Center of Wisconsin, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Wisconsin, United States of America
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| |
Collapse
|
47
|
Stone NR, Rhodes J, Fisher MC, Mfinanga S, Kivuyo S, Rugemalila J, Segal ES, Needleman L, Molloy SF, Kwon-Chung J, Harrison TS, Hope W, Berman J, Bicanic T. Dynamic ploidy changes drive fluconazole resistance in human cryptococcal meningitis. J Clin Invest 2019; 129:999-1014. [PMID: 30688656 PMCID: PMC6391087 DOI: 10.1172/jci124516] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/30/2018] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Cryptococcal meningitis (CM) causes an estimated 180,000 deaths annually, predominantly in sub-Saharan Africa, where most patients receive fluconazole (FLC) monotherapy. While relapse after FLC monotherapy with resistant strains is frequently observed, the mechanisms and impact of emergence of FLC resistance in human CM are poorly understood. Heteroresistance (HetR) - a resistant subpopulation within a susceptible strain - is a recently described phenomenon in Cryptococcus neoformans (Cn) and Cryptococcus gattii (Cg), the significance of which has not previously been studied in humans. METHODS A cohort of 20 patients with HIV-associated CM in Tanzania was prospectively observed during therapy with either FLC monotherapy or in combination with flucytosine (5FC). Total and resistant subpopulations of Cryptococcus spp. were quantified directly from patient cerebrospinal fluid (CSF). Stored isolates underwent whole genome sequencing and phenotypic characterization. RESULTS Heteroresistance was detectable in Cryptococcus spp. in the CSF of all patients at baseline (i.e., prior to initiation of therapy). During FLC monotherapy, the proportion of resistant colonies in the CSF increased during the first 2 weeks of treatment. In contrast, no resistant subpopulation was detectable in CSF by day 14 in those receiving a combination of FLC and 5FC. Genomic analysis revealed high rates of aneuploidy in heteroresistant colonies as well as in relapse isolates, with chromosome 1 (Chr1) disomy predominating. This is apparently due to the presence on Chr1 of ERG11, which is the FLC drug target, and AFR1, which encodes a drug efflux pump. In vitro efflux levels positively correlated with the level of heteroresistance. CONCLUSION Our findings demonstrate for what we believe is the first time the presence and emergence of aneuploidy-driven FLC heteroresistance in human CM, association of efflux levels with heteroresistance, and the successful suppression of heteroresistance with 5FC/FLC combination therapy. FUNDING This work was supported by the Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377/Z/11/Z and the Daniel Turnberg Travel Fellowship.
Collapse
Affiliation(s)
- Neil R.H. Stone
- Centre for Global Health, Institute for Infection and Immunity, St. George’s, University of London, United Kingdom
| | - Johanna Rhodes
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
| | - Matthew C. Fisher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
| | - Sayoki Mfinanga
- National Institute of Medical Research, Dar es Salaam, Tanzania
- Liverpool School of Tropical Medicine, United Kingdom
| | - Sokoine Kivuyo
- National Institute of Medical Research, Dar es Salaam, Tanzania
| | | | - Ella Shtifman Segal
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Israel
| | - Leor Needleman
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Israel
| | - Síle F. Molloy
- Centre for Global Health, Institute for Infection and Immunity, St. George’s, University of London, United Kingdom
| | | | - Thomas S. Harrison
- Centre for Global Health, Institute for Infection and Immunity, St. George’s, University of London, United Kingdom
| | - William Hope
- Institute of Translational Medicine, University of Liverpool, United Kingdom
| | - Judith Berman
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Israel
| | - Tihana Bicanic
- Centre for Global Health, Institute for Infection and Immunity, St. George’s, University of London, United Kingdom
| |
Collapse
|
48
|
Calvete CL, Martho KF, Felizardo G, Paes A, Nunes JM, Ferreira CO, Vallim MA, Pascon RC. Amino acid permeases in Cryptococcus neoformans are required for high temperature growth and virulence; and are regulated by Ras signaling. PLoS One 2019; 14:e0211393. [PMID: 30682168 PMCID: PMC6347259 DOI: 10.1371/journal.pone.0211393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/11/2019] [Indexed: 11/22/2022] Open
Abstract
Cryptococcosis is an Invasive Fungal Infection (IFI) caused by Cryptococcus neoformans, mainly in immunocompromised patients. Therapeutic failure due to pathogen drug resistance, treatment inconstancy and few antifungal options is a problem. The study of amino acid biosynthesis and uptake represents an opportunity to explore possible development of novel antifungals. C. neoformans has 10 amino acids permeases, two of them (Aap3 and Aap7) not expressed at the conditions tested, and five were studied previously (Aap2, Aap4, Aap5, Mup1 and Mup3). Our previous results showed that Aap4 and Aap5 are major permeases with overlapping functions. The aap4Δ/aap5Δ double mutant fails to grow in amino acids as sole nitrogen source and is avirulent in animal model. Here, we deleted the remaining amino acid permeases (AAP1, AAP6, AAP8) that showed gene expression modulation by nutritional condition and created a double mutant (aap1Δ/aap2Δ). We studied the virulence attributes of these mutants and explored the regulatory mechanism behind amino acid uptake in C. neoformans. The aap1Δ/aap2Δ strain had reduced growth at 37°C in L-amino acids, reduced capsule production and was hypovirulent in the Galleria mellonella animal model. Our data, along with previous studies, (i) complement the analysis for all 10 amino acid permeases mutants, (ii) corroborate the idea that these transporters behave as global permeases, (iii) are required during heat and nutritional stress, and (iv) are important for virulence. Our study also indicates a new possible link between Ras1 signaling and amino acids uptake.
Collapse
Affiliation(s)
- Crislaine Lambiase Calvete
- Universidade de São Paulo, Biotechnology Graduate Program, São Paulo, SP, Brazil
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Kevin Felipe Martho
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Gabrielle Felizardo
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Alexandre Paes
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - João Miguel Nunes
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Camila Oliveira Ferreira
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Marcelo A. Vallim
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Renata C. Pascon
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
- * E-mail:
| |
Collapse
|
49
|
Boyce K, Morrissey O, Idnurm A, Macreadie I. Insights into the global emergence of antifungal drug resistance. MICROBIOLOGY AUSTRALIA 2019. [DOI: 10.1071/ma19024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The global prevalence of fungal diseases has escalated in the last several decades. Currently, it is estimated that fungi infect 1.7 billion people annually and result in 1.5 million deaths every year1. Deaths due to fungal infections are increasing, with mortality often exceeding 50%, further increasing to 100% if treatment is delayed1. Despite these staggering figures, the contribution of fungal infections to the global burden of disease remains under-recognised. In Australia, over a 5-year period fungal infections cost Australia an estimated $583 million2. The median cost for one invasive fungal disease (IFD) is AU$30957, increasing to AU$80291 if the patient is admitted to an intensive care unit3. Treatment of fungal infections poses significant challenges due to the small number of safe and effective antifungal drugs available and emerging antifungal drug resistance. Resistance to every class of antifungal drugs has been described and for some drug classes is extremely common4,5.
Collapse
|
50
|
Cissé OH, Hauser PM. Genomics and evolution of Pneumocystis species. INFECTION GENETICS AND EVOLUTION 2018; 65:308-320. [PMID: 30138710 DOI: 10.1016/j.meegid.2018.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 01/20/2023]
Abstract
The genus Pneumocystis comprises highly diversified fungal species that cause severe pneumonia in individuals with a deficient immune system. These fungi infect exclusively mammals and present a strict host species specificity. These species have co-diverged with their hosts for long periods of time (> 100 MYA). Details of their biology and evolution are fragmentary mainly because of a lack of an established long-term culture system. Recent genomic advances have unlocked new areas of research and allow new hypotheses to be tested. We review here new findings of the genomic studies in relation with the evolutionary trajectory of these fungi and discuss the impact of genomic data analysis in the context of the population genetics. The combination of slow genome decay and limited expansion of specific gene families and introns reflect intimate interactions of these species with their hosts. The evolutionary adaptation of these organisms is profoundly influenced by their population structure, which in turn is determined by intrinsic features such as their self-fertilizing mating system, high host specificity, long generation times, and transmission mode. Essential key questions concerning their adaptation and speciation remain to be answered. The next cornerstone will consist in the establishment of a long-term culture system and genetic manipulation that should allow unravelling the driving forces of Pneumocystis species evolution.
Collapse
Affiliation(s)
- Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland.
| |
Collapse
|