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Stuckey PV, Santiago-Tirado FH. Fungal mechanisms of intracellular survival: what can we learn from bacterial pathogens? Infect Immun 2023; 91:e0043422. [PMID: 37506189 PMCID: PMC10501222 DOI: 10.1128/iai.00434-22] [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: 11/28/2022] [Accepted: 06/23/2023] [Indexed: 07/30/2023] Open
Abstract
Fungal infections represent a major, albeit neglected, public health threat with serious medical and economic burdens globally. With unacceptably high mortality rates, invasive fungal pathogens are responsible for millions of deaths each year, with a steadily increasing incidence primarily in immunocompromised individuals. The poor therapeutic options and rise of antifungal drug resistance pose further challenges in controlling these infections. These fungal pathogens have adapted to survive within mammalian hosts and can establish intracellular niches to promote survival within host immune cells. To do that, they have developed diverse methods to circumvent the innate immune system attack. This includes strategies such as altering their morphology, counteracting macrophage antimicrobial action, and metabolic adaptation. This is reminiscent of how bacterial pathogens have adapted to survive within host cells and cause disease. However, relative to the great deal of information available concerning intracellular bacterial pathogenesis, less is known about the mechanisms fungal pathogens employ. Therefore, here we review our current knowledge and recent advances in our understanding of how fungi can evade and persist within host immune cells. This review will focus on the major fungal pathogens, including Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus, among others. As we discover and understand the strategies used by these fungi, similarities with their bacterial counterparts are becoming apparent, hence we can use the abundant information from bacteria to guide our studies in fungi. By understanding these strategies, new lines of research will open that can improve the treatments of these devastating fungal diseases.
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Affiliation(s)
- Peter V. Stuckey
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Felipe H. Santiago-Tirado
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
- Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana, USA
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Gene, virulence and related regulatory mechanisms in Cryptococcus gattii. Acta Biochim Biophys Sin (Shanghai) 2022; 54:593-603. [PMID: 35593469 PMCID: PMC9828318 DOI: 10.3724/abbs.2022029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cryptococcus gattii is a kind of basidiomycetous yeast, which grows in human and animal hosts. C. gattii has four distinct genomes, VGI/AFLP4, VGII/AFLP6, VGIII/AFLP5, and VGIV/AFLP7. The virulence of C. gattii is closely associated with genotype and related stress-signaling pathways, but the pathogenic mechanism of C. gattii has not been fully identified. With the development of genomics and transcriptomics, the relationship among genes, regulatory mechanisms, virulence, and treatment is gradually being recognized. In this review, to better understand how C. gattii causes disease and to characterize hypervirulent C. gattii strains, we summarize the current understanding of C. gattii genotypes, phenotypes, virulence, and the regulatory mechanisms.
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Dangarembizi R. Reimagining the future of African brain health: Perspectives for basic research on the pathogenesis of cryptococcal meningitis. Brain Behav Immun Health 2021; 18:100388. [PMID: 34825235 PMCID: PMC8605210 DOI: 10.1016/j.bbih.2021.100388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 10/28/2021] [Accepted: 11/05/2021] [Indexed: 11/24/2022] Open
Abstract
Cryptococcal meningitis is a fatal opportunistic infection of the brain and a leading cause of neurological damage and death in immunocompromised individuals. This neglected fungal disease of the brain is a huge burden on the health systems of developing countries, especially in Sub-Saharan Africa, where up to 25% of people living with HIV/AIDS succumb to it. Cryptococcal fungal cells have a predilection for the brain and they are capable of traversing the blood brain barrier and invade the brain where they cause infection, inflammation and a disruption of normal brain function. A robust host neuroimmune response is critical for pathogen clearance and survival, and a good understanding of the mechanisms underlying its development in the host is critical for the development of effective treatments. However, past basic research studies have been focussed on the characteristics of the fungus and its effect on the peripheral immune system; with little attention paid to how it interacts with brain immune cells. This mini review briefly discusses the paucity of basic research data on the neuroimmune response to cryptococcal infection, raises pertinent questions on how the brain cells respond to the fungal infection, and thereafter discusses models, techniques and advanced technologies that could be useful for carrying out high-throughput research on the pathogenesis of cryptococcal meningitis.
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Affiliation(s)
- R Dangarembizi
- Division of Physiological Sciences, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Neuroscience Institute, Faculty of Health Sciences, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa
- CMM AFRICA Medical Mycology Research Unit, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Fisher KM, Montrief T, Ramzy M, Koyfman A, Long B. Cryptococcal meningitis: a review for emergency clinicians. Intern Emerg Med 2021; 16:1031-1042. [PMID: 33420904 DOI: 10.1007/s11739-020-02619-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 12/23/2020] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Cryptococcal Meningitis (CM) remains a high-risk clinical condition, and many patients require emergency department (ED) management for complications and stabilization. OBJECTIVE This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of CM. DISCUSSION This review evaluates the diagnosis, management, and empiric treatment of suspected CM in the ED. CM can easily evade diagnosis with a subacute presentation, and should be considered in any patient with a headache, neurological deficit, or who is immunocompromised. As a definitive diagnosis of CM will not be made in the ED, management of a patient with suspected CM includes prompt diagnostic testing and initiation of empiric treatment. Multiple types of newer Cryptococcal antigen tests provide high sensitivity and specificity both in serum and cerebrospinal fluid (CSF). Patients should be treated empirically for bacterial, fungal, and viral meningitis, specifically with amphotericin B and flucytosine for presumed CM. Additionally, appropriate resuscitation and supportive care, including advanced airway management, management of increased intracranial pressure (ICP), antipyretics, intravenous fluids, and isolation, should be initiated. Antiretroviral therapy (ART) should not be initiated in the ED for those found or known to be HIV-positive for risk of immune reconstitution inflammatory syndrome (IRIS). CONCLUSIONS CM remains a rare clinical presentation, but carries significant morbidity and mortality. Physicians must rapidly diagnose these patients while evaluating for other diseases and complications. Early consultation with an infectious disease specialist is imperative, as is initiating symptomatic care.
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Affiliation(s)
- Kathryn Marie Fisher
- Department of Emergency Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Tim Montrief
- Department of Critical Care Medicine, University of Pittsburgh Medical Center, 3550 Terrace St., Pittsburgh, PA, 15261, USA
| | - Mark Ramzy
- Department of Critical Care Medicine, University of Pittsburgh Medical Center, 3550 Terrace St., Pittsburgh, PA, 15261, USA
| | - Alex Koyfman
- Department of Emergency Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Brit Long
- Department of Emergency Medicine, Brooke Army Medical Center, 3841 Roger Brooke Dr, Fort Sam Houston, TX, 78234, USA.
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Concurrent Pulmonary and Cerebellar Cryptococcus Gattii Cryptococcoma in an Apparently Immunocompetent Patient in Florida. Case Rep Infect Dis 2021. [DOI: 10.1155/2021/5564520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cryptococcus infection is caused by one of the two species, Cryptococcus neoformans, or the less common Cryptococcus gattii. While Cryptococcus neoformans commonly infects the immunocompromised population, Cryptococcus gattii has been seen more frequently in immunocompetent patients. Many seemingly immunocompetent patients, however, may have unidentified underlying immunodeficiencies. Recently, antigranulocyte-macrophage colony-stimulating (GM-CSF) antibodies have been identified as a risk factor for cryptococcosis. We describe a case of disseminated Cryptococcus gattii infection in a seemingly immunocompetent young man, who is found to have anti-GM-CSF antibodies.
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Abstract
Cryptococcus yeast species typically display characteristics of opportunistic pathogens, with the exception of C. gattii, which can cause life-threatening respiratory and disseminated brain infections in otherwise healthy people. The pathogenesis of C. gattii is not well understood, but an important characteristic is that C. gattii is capable of evading host cell-mediated immune defenses initiated by DCs. Here, we report that when virulent C. gattii becomes ingested by a DC, the intracellular compartment containing the fungi is covered by a persistent protein cage structure consisting of F-actin. This F-actin cage acts as a barrier to prevent interaction with other intracellular compartments, and as a result, the DC fails to kill the fungi and activate important cell-mediated immune responses. We propose that this unique immune evasion mechanism permits C. gattii to remain unchallenged within host cells, leading to persistent infection. Cryptococcus gattii is a major cause of life-threatening mycosis in immunocompetent individuals and responsible for the ongoing epidemic outbreak of cryptococcosis in the Pacific Northwest of North America. This deadly fungus is known to evade important host immune responses, including dendritic cell (DC) maturation and concomitant T cell immunity, via immune evasion mechanisms that remain unclear. Here, we demonstrate that primary human DCs phagocytose C. gattii but the maturation of phagosomes to phagolysosomes was blocked as a result of sustained filamentous actin (F-actin) that entrapped and concealed the phagosomes from recognition. Superresolution structured illumination microscopy (SR-SIM) revealed that the persistent phagosomal F-actin formed a cage-like structure that sterically hindered and functionally blocked the fusion of lysosomes. Blocking lysosome fusion was sufficient to inhibit phagosomal acidification and subsequent intracellular fungal killing by DCs. Retention of phagosomal F-actin by C. gattii also caused DC immunoparalysis. Disrupting the retained F-actin cage with cytochalasin D not only restored DC phagosomal maturation but also promoted DC costimulatory maturation and robust T cell activation and proliferation. Collectively, these results reveal a unique mechanism of DC immune evasion that enhances intracellular fungal pathogenicity and may explain suppressed cell-mediated immunity.
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Hurst S, Lysen C, Cooksey G, Vugia DJ, Litvintseva AP, Lockhart SR. Molecular typing of clinical and environmental isolates of Cryptococcus gattii species complex from southern California, United States. Mycoses 2019; 62:1029-1034. [PMID: 31376185 DOI: 10.1111/myc.12980] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Two species complexes (SC) cause the majority of human Cryptococcus infections: Cryptococcus neoformans SC and Cryptococcus gattii SC. Infection is typically thought to be acquired following environmental exposure. In an urban setting, parks and other public spaces are a likely source of contact with C. gattii SC. OBJECTIVES The goals of this study were to describe the genetic diversity of C. gattii SC in the California environment, to determine the extent of environmental exposure in publicly accessed areas and to correlate the genotypes of environmental C. gattii SC isolates with those from patients in southern California. METHODS Specimens from trees and soil from 13 parks and public areas of seven California counties were examined for C. gattii SC isolates. Isolates were sequence typed and compared to sequence types from human clinical isolates from the same area. RESULTS Multilocus sequence typing identified C. gattii sensu stricto (VGI molecular type) as well as Cryptococcus bacillisporus (VGIII molecular type). Several C. bacillisporus but none of the C. gattii sensu stricto isolates shared sequence types with human clinical isolates from southern California. CONCLUSIONS C. gattii SC colonies exist in some California public parks. The presence of identical STs in environmental and human isolates of C. bacillisporus is suggestive of an arboreal origin of human infections. Two new tree species were documented as hosts for C. gattii SC in California, adding to the four species previously identified.
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Affiliation(s)
- Steven Hurst
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Colleen Lysen
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Gail Cooksey
- Infectious Disease Branch, California Department of Public Health, Richmond, CA, USA
| | - Duc J Vugia
- Infectious Disease Branch, California Department of Public Health, Richmond, CA, USA
| | | | - Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Bruner KT, Franco-Paredes C, Henao-Martínez AF, Steele GM, Chastain DB. Cryptococcus gattii Complex Infections in HIV-Infected Patients, Southeastern United States. Emerg Infect Dis 2019; 24:1998-2002. [PMID: 30334702 PMCID: PMC6199986 DOI: 10.3201/eid2411.180787] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Increased awareness of C. gattii infections in these patients is critical for improving diagnosis, treatment, and outcomes. Cryptococcus gattii traditionally infects immunocompetent hosts and causes devastating pulmonary or central nervous system disease. However, this infection rarely occurs in patients infected with HIV. We report 3 cases of HIV-associated C. gattii complex infections in the southeastern United States. Detection of C. gattii in HIV-infected patients in this region warrants increased awareness of this threat to ensure appropriate diagnosis and treatment to optimize patient outcomes.
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Vreulink JM, Khayhan K, Hagen F, Botes A, Moller L, Boekhout T, Vismer H, Botha A. Presence of pathogenic cryptococci on trees situated in two recreational areas in South Africa. FUNGAL ECOL 2017. [DOI: 10.1016/j.funeco.2017.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tuberculosis/cryptococcosis co-infection in China between 1965 and 2016. Emerg Microbes Infect 2017; 6:e73. [PMID: 28831193 PMCID: PMC5583669 DOI: 10.1038/emi.2017.61] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 05/23/2017] [Accepted: 06/11/2017] [Indexed: 11/08/2022]
Abstract
Cases of tuberculosis/cryptococcosis co-infection are rapidly increasing in China. However, most studies addressing this co-infection have been published in Chinese journals, and this publication strategy has obscured this disease trend for scientists in other parts of the world. Our investigation found that 62.9% of all co-infection cases worldwide were reported in the Chinese population (n=197) between 1965 and 2016, and 56.3% of these Chinese cases were reported after 2010. Nearly all cases originated from the warm and wet monsoon regions of China. HIV-positive subjects tended to correlate with more severe manifestations of a tuberculosis/cryptococcosis co-infection than those without HIV. Notablely, dual tubercular/cryptococcal meningitis was the most frequent (54.0%) and most easily misdiagnosed (95.2%, n=40/42) co-infection. We also found that the combined use of cerebrospinal fluid pressure and concentrations of glucose, protein and chlorine might be an inexpensive and effective indicator to differentiate tubercular/cryptococcal co-infection meningitis from tubercular meningitis and cryptococcal meningitis.
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Emerging Fungal Infections in the Pacific Northwest: The Unrecognized Burden and Geographic Range of Cryptococcus gattii and Coccidioides immitis. Microbiol Spectr 2017; 4. [PMID: 27337452 DOI: 10.1128/microbiolspec.ei10-0016-2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Both Cryptococcus gattii and Coccidioides can cause debilitating diseases if not identified early. It is imperative that clinicians recognize these diseases and begin treatment quickly when necessary. In order to have these two mycoses in their differential diagnosis, clinicians, microbiologists, and public health officials must be aware of the expanding geographic boundary in the case of Coccidioides immitis and the new emergence in the case of C. gattii. Accordingly, there is now mandatory reporting for cases of C. gattii and C. immitis in both Washington and Oregon, and the Centers for Disease Control and Prevention keeps a repository of available isolates. Through the One Health initiative, clinicians, veterinarians, and public health officials are collaborating to better understand the emergence and expanding geographic range of these extremely important fungal diseases.
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Firacative C, Roe CC, Malik R, Ferreira-Paim K, Escandón P, Sykes JE, Castañón-Olivares LR, Contreras-Peres C, Samayoa B, Sorrell TC, Castañeda E, Lockhart SR, Engelthaler DM, Meyer W. MLST and Whole-Genome-Based Population Analysis of Cryptococcus gattii VGIII Links Clinical, Veterinary and Environmental Strains, and Reveals Divergent Serotype Specific Sub-populations and Distant Ancestors. PLoS Negl Trop Dis 2016; 10:e0004861. [PMID: 27494185 PMCID: PMC4975453 DOI: 10.1371/journal.pntd.0004861] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 06/29/2016] [Indexed: 12/13/2022] Open
Abstract
The emerging pathogen Cryptococcus gattii causes life-threatening disease in immunocompetent and immunocompromised hosts. Of the four major molecular types (VGI-VGIV), the molecular type VGIII has recently emerged as cause of disease in otherwise healthy individuals, prompting a need to investigate its population genetic structure to understand if there are potential genotype-dependent characteristics in its epidemiology, environmental niche(s), host range and clinical features of disease. Multilocus sequence typing (MLST) of 122 clinical, environmental and veterinary C. gattii VGIII isolates from Australia, Colombia, Guatemala, Mexico, New Zealand, Paraguay, USA and Venezuela, and whole genome sequencing (WGS) of 60 isolates representing all established MLST types identified four divergent sub-populations. The majority of the isolates belong to two main clades, corresponding either to serotype B or C, indicating an ongoing species evolution. Both major clades included clinical, environmental and veterinary isolates. The C. gattii VGIII population was genetically highly diverse, with minor differences between countries, isolation source, serotype and mating type. Little to no recombination was found between the two major groups, serotype B and C, at the whole and mitochondrial genome level. C. gattii VGIII is widespread in the Americas, with sporadic cases occurring elsewhere, WGS revealed Mexico and USA as a likely origin of the serotype B VGIII population and Colombia as a possible origin of the serotype C VGIII population. Serotype B isolates are more virulent than serotype C isolates in a murine model of infection, causing predominantly pulmonary cryptococcosis. No specific link between genotype and virulence was observed. Antifungal susceptibility testing against six antifungal drugs revealed that serotype B isolates are more susceptible to azoles than serotype C isolates, highlighting the importance of strain typing to guide effective treatment to improve the disease outcome. Cryptococcus gattii, which is classically divided into four major molecular types (VGI-VGIV), and two serotypes B and C, is the second most important cause of cryptococcosis. The rising incidence of human and animal cryptococcosis cases caused by molecular type VGIII highlights the need for increased vigilance. In this study, we characterized a large set of C. gattii VGIII isolates. Genetic analysis revealed four diverging sub-populations, which were primarily associated with serotype B or C, and very likely originated from endemic regions in Colombia, Mexico and the USA. Differences in virulence and antifungal susceptibility between serotypes may result in different disease outcomes since serotype B isolates were more virulent in mice than serotype C isolates, but serotype C isolates were less susceptible to azoles, the primary treatment for uncomplicated cryptococcosis. Identification of cryptococcal serotype and molecular type in clinical practice has the potential to guide treatment regimens and hence reduce morbidity and mortality in both sporadic cases and those associated with outbreaks. Our study significantly contributes to the understanding of the epidemiology, genetics and pathogenesis of Cryptococcus and cryptococcosis.
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Affiliation(s)
- Carolina Firacative
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
- Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, Colombia
| | - Chandler C. Roe
- Translational Genomics Research Institute, Flagstaff, Arizona, United States of America
| | - Richard Malik
- Centre for Veterinary Education, The University of Sydney, Sydney, Australia
| | - Kennio Ferreira-Paim
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
- Infectious Disease Department, Triangulo Mineiro Federal University, Uberaba, Minas Gerais, Brazil
| | - Patricia Escandón
- Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, Colombia
| | - Jane E. Sykes
- Department of Medicine and Epidemiology, University of California, Davis, Davis, California, United States of America
| | - Laura Rocío Castañón-Olivares
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad National Autónoma de México, Mexico City, Mexico
| | | | | | - Tania C. Sorrell
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
| | | | - Shawn R. Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - David M. Engelthaler
- Translational Genomics Research Institute, Flagstaff, Arizona, United States of America
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
- * E-mail:
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Kwon-Chung KJ, Saijo T. Is Cryptococcus gattii a Primary Pathogen? J Fungi (Basel) 2015; 1:154-167. [PMID: 27795955 PMCID: PMC5084617 DOI: 10.3390/jof1020154] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/09/2015] [Indexed: 01/01/2023] Open
Abstract
The two etiologic agents of cryptococcal meningoencephalitis, Cryptococcus neoformans and C. gattii, have been commonly designated as either an opportunistic pathogen for the first species or as a primary pathogen for the second species. Such a distinction has been based on epidemiological findings that the majority of patients presenting meningoencephalitis caused by C. neoformans are immunocompromised while C. gattii infection has been reported more often in immunocompetent patients. A recent report, however, showed that GM-CSF (granulocyte-macrophage colony-stimulating factor) neutralizing antibodies were prevalent in the plasma of "apparently immunocompetent" C. gattii patients with meningoencephalitis. Because GM-CSF is essential for differentiation of monocytes to macrophages and modulating the immune response, it is not surprising that the lack of GM-CSF function predisposes otherwise healthy individuals to infection via inhalation of environmental pathogens such as C. gattii. Since the test for anti-GM-CSF autoantibodies is not included in routine immunological profiling at most hospitals, healthy patients with GM-CSF neutralizing antibodies are usually categorized as immunocompetent. It is likely that a comprehensive immunological evaluation of patients with C. gattii meningoencephalitis, who had been diagnosed as immunocompetent, would reveal a majority of them had hidden immune dysfunction. This paper reviews the relationship between GM-CSF neutralizing antibodies and the risk for C. gattii infection with CNS involvement.
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Affiliation(s)
- Kyung J. Kwon-Chung
- Molecular Microbiology Section, Laboratory of Clinical Infectious Diseases, National Institutes of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Tomomi Saijo
- Second Department of Internal Medicine, Nagasaki University Hospital, Sakamoto 1-7-1, Nagasaki-city, 851-8501, Japan; E-Mail:
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Rodrigues J, Fonseca FL, Schneider RO, Godinho RMDC, Firacative C, Maszewska K, Meyer W, Schrank A, Staats C, Kmetzsch L, Vainstein MH, Rodrigues ML. Pathogenic diversity amongst serotype C VGIII and VGIV Cryptococcus gattii isolates. Sci Rep 2015; 5:11717. [PMID: 26153364 PMCID: PMC4495446 DOI: 10.1038/srep11717] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/27/2015] [Indexed: 12/11/2022] Open
Abstract
Cryptococcus gattii is one of the causative agents of human cryptococcosis. Highly virulent strains of serotype B C. gattii have been studied in detail, but little information is available on the pathogenic properties of serotype C isolates. In this study, we analyzed pathogenic determinants in three serotype C C. gattii isolates (106.97, ATCC 24066 and WM 779). Isolate ATCC 24066 (molecular type VGIII) differed from isolates WM 779 and 106.97 (both VGIV) in capsule dimensions, expression of CAP genes, chitooligomer distribution, and induction of host chitinase activity. Isolate WM 779 was more efficient than the others in producing pigments and all three isolates had distinct patterns of reactivity with antibodies to glucuronoxylomannan. This great phenotypic diversity reflected in differential pathogenicity. VGIV isolates WM 779 and 106.97 were similar in their ability to cause lethality and produced higher pulmonary fungal burden in a murine model of cryptococcosis, while isolate ATCC 24066 (VGIII) was unable to reach the brain and caused reduced lethality in intranasally infected mice. These results demonstrate a high diversity in the pathogenic potential of isolates of C. gattii belonging to the molecular types VGIII and VGIV.
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Affiliation(s)
- Jéssica Rodrigues
- Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda L Fonseca
- Fundação Oswaldo Cruz - Fiocruz, Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Rio de Janeiro, Brazil
| | - Rafael O Schneider
- Centro de Biotecnologia, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Rodrigo M da C Godinho
- Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carolina Firacative
- 1] Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia [2] Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, Colombia
| | - Krystyna Maszewska
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School - Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
| | - Augusto Schrank
- Centro de Biotecnologia, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Charley Staats
- Centro de Biotecnologia, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Livia Kmetzsch
- Centro de Biotecnologia, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Marilene H Vainstein
- Centro de Biotecnologia, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Marcio L Rodrigues
- 1] Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil [2] Fundação Oswaldo Cruz - Fiocruz, Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Rio de Janeiro, Brazil
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Abstract
Understanding of the taxonomy and phylogeny of Cryptococcus gattii has been advanced by modern molecular techniques. C. gattii probably diverged from Cryptococcus neoformans between 16 million and 160 million years ago, depending on the dating methods applied, and maintains diversity by recombining in nature. South America is the likely source of the virulent C. gattii VGII molecular types that have emerged in North America. C. gattii shares major virulence determinants with C. neoformans, although genomic and transcriptomic studies revealed that despite similar genomes, the VGIIa and VGIIb subtypes employ very different transcriptional circuits and manifest differences in virulence phenotypes. Preliminary evidence suggests that C. gattii VGII causes severe lung disease and death without dissemination, whereas C. neoformans disseminates readily to the central nervous system (CNS) and causes death from meningoencephalitis. Overall, currently available data indicate that the C. gattii VGI, VGII, and VGIII molecular types more commonly affect nonimmunocompromised hosts, in contrast to VGIV. New, rapid, cheap diagnostic tests and imaging modalities are assisting early diagnosis and enabling better outcomes of cerebral cryptococcosis. Complications of CNS infection include increased intracranial pressure, severe neurological sequelae, and development of immune reconstitution syndrome, although the mortality rate is low. C. gattii VGII isolates may exhibit higher fluconazole MICs than other genotypes. Optimal therapeutic regimens are yet to be determined; in most cases, initial therapy with amphotericin B and 5-flucytosine is recommended.
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Espinel-Ingroff A, Kidd SE. Current trends in the prevalence of Cryptococcus gattii in the United States and Canada. Infect Drug Resist 2015; 8:89-97. [PMID: 25999744 PMCID: PMC4437038 DOI: 10.2147/idr.s57686] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The incidence of Cryptococcus gattii infections in both Canada and the United States (US) is provided in this literature review beyond the British Columbia (BC) outbreak (1999-2013). Based on a search of the literature, case reports of C. gattii human infections including the prevalent molecular genotypes causing these infections in both Canada and the US have been documented since the C. gattii outbreak in BC. The literature reveals that: i) although C. gattii infections continue to be reported in both countries, the preliminary overall number of confirmed C. gattii infections may be decreasing in both Canada and the US (~23 cases each in 2012 versus ~17 and 20 cases, respectively in 2013); ii) C. gattii genotype distribution is region-dependent; iii) C. gattii is more frequently isolated from infections in the immunocompromised host (including acquired immune deficiency syndrome [AIDS] infection) than previously expected; iv) although pulmonary disease is higher than in C. neoformans infections, central nervous system disease is also reported among patients infected with C. gattii.
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Affiliation(s)
| | - Sarah E Kidd
- National Mycology Reference Center, SA Pathology, Adelaide, SA, Australia
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Hagen F, Khayhan K, Theelen B, Kolecka A, Polacheck I, Sionov E, Falk R, Parnmen S, Lumbsch HT, Boekhout T. Recognition of seven species in the Cryptococcus gattii/Cryptococcus neoformans species complex. Fungal Genet Biol 2015; 78:16-48. [PMID: 25721988 DOI: 10.1016/j.fgb.2015.02.009] [Citation(s) in RCA: 460] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/12/2015] [Accepted: 02/15/2015] [Indexed: 02/08/2023]
Abstract
Phylogenetic analysis of 11 genetic loci and results from many genotyping studies revealed significant genetic diversity with the pathogenic Cryptococcus gattii/Cryptococcus neoformans species complex. Genealogical concordance, coalescence-based, and species tree approaches supported the presence of distinct and concordant lineages within the complex. Consequently, we propose to recognize the current C. neoformans var. grubii and C. neoformans var. neoformans as separate species, and five species within C. gattii. The type strain of C. neoformans CBS132 represents a serotype AD hybrid and is replaced. The newly delimited species differ in aspects of pathogenicity, prevalence for patient groups, as well as biochemical and physiological aspects, such as susceptibility to antifungals. MALDI-TOF mass spectrometry readily distinguishes the newly recognized species.
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Affiliation(s)
- Ferry Hagen
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands; Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Kantarawee Khayhan
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands; Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand
| | - Bart Theelen
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands
| | - Anna Kolecka
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands
| | - Itzhack Polacheck
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
| | - Edward Sionov
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel; Department of Food Quality & Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Rama Falk
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel; Department of Fisheries and Aquaculture, Ministry of Agriculture and Rural Development, Nir-David, Israel
| | - Sittiporn Parnmen
- Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand
| | | | - Teun Boekhout
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands; Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China; Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
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Ren P, Chaturvedi V, Chaturvedi S. Carbon dioxide is a powerful inducer of monokaryotic hyphae and spore development in Cryptococcus gattii and carbonic anhydrase activity is dispensable in this dimorphic transition. PLoS One 2014; 9:e113147. [PMID: 25478697 PMCID: PMC4257545 DOI: 10.1371/journal.pone.0113147] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 10/22/2014] [Indexed: 12/02/2022] Open
Abstract
Cryptococcus gattii is unique among human pathogenic fungi with specialized ecological niche on trees. Since leaves concentrate CO2, we investigated the role of this gaseous molecule in C. gattii biology and virulence. We focused on the genetic analyses of β-carbonic anhydrase (β-CA) encoded by C. gattii CAN1 and CAN2 as later is critical for CO2 sensing in a closely related pathogen C. neoformans. High CO2 conditions induced robust development of monokaryotic hyphae and spores in C. gattii. Conversely, high CO2 completely repressed hyphae development in sexual mating. Both CAN1 and CAN2 were dispensable for CO2 induced morphogenetic transitions. However, C. gattii CAN2 was essential for growth in ambient air similar to its reported role in C. neoformans. Both can1 and can2 mutants retained full pathogenic potential in vitro and in vivo. These results provide insight into C. gattii adaptation for arboreal growth and production of infectious propagules by β-CA independent mechanism(s).
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Affiliation(s)
- Ping Ren
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, New York, United States of America
| | - Vishnu Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, New York, United States of America; Department of Biomedical Sciences, School of Public Health, State University at New York, Albany, New York, United States of America
| | - Sudha Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, New York, United States of America; Department of Biomedical Sciences, School of Public Health, State University at New York, Albany, New York, United States of America
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Franco-Paredes C, Womack T, Bohlmeyer T, Sellers B, Hays A, Patel K, Lizarazo J, Lockhart SR, Siddiqui W, Marr KA. Management of Cryptococcus gattii meningoencephalitis. THE LANCET. INFECTIOUS DISEASES 2014; 15:348-55. [PMID: 25467646 DOI: 10.1016/s1473-3099(14)70945-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cryptococcosis is a fungal disease caused by Cryptococcus neoformans and Cryptococcus gattii. By inhalation and subsequent pulmonary infection, it may disseminate to the CNS and cause meningitis or meningoencephalitis. Most cases occur in immunosuppressed hosts, including patients with HIV/AIDS, patients receiving immunosuppressing drugs, and solid organ transplant recipients. However, cryptococcosis also occurs in individuals with apparently healthy immune systems. A growing number of cases are caused by C gattii, with infections occurring in both immunosuppressed and immunocompetent individuals. In the majority of documented cases, treatment of C gattii infection of the CNS requires aggressive management of raised intracranial pressure along with standard antifungal therapy. Early cerebrospinal fluid evacuation is often needed through placement of a percutaneous lumbar drain or ventriculostomy. Furthermore, pharmacological immunosuppression with a high dose of dexamethasone is sometimes needed to ameliorate a persistently increased inflammatory response and to reduce intracranial pressure. In this Grand Round, we present the case of an otherwise healthy adolescent female patient, who, despite aggressive management, succumbed to C gattii meningoencephalitis. We also present a review of the existing literature and discuss optimum clinical management of meningoencephalitis caused by C gattii.
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Affiliation(s)
- Carlos Franco-Paredes
- Phoebe Putney Memorial Hospital, Albany, GA, USA; Hospital Infantil de Mexico, Federico Gomez, Mexico City, Mexico.
| | - Tanea Womack
- Phoebe Putney Memorial Hospital, Albany, GA, USA
| | | | | | - Allison Hays
- Phoebe Putney Memorial Hospital, Albany, GA, USA
| | | | - Jairo Lizarazo
- Hospital Universitario Erasmo Meoz, Cúcuta, Norte de Santander, Colombia
| | | | | | - Kieren A Marr
- Johns Hopkins University Medical Center, Baltimore, MD, USA; the Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD, USA
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Lizarazo J, Escandón P, Agudelo CI, Firacative C, Meyer W, Castañeda E. Retrospective study of the epidemiology and clinical manifestations of Cryptococcus gattii infections in Colombia from 1997-2011. PLoS Negl Trop Dis 2014; 8:e3272. [PMID: 25411779 PMCID: PMC4238989 DOI: 10.1371/journal.pntd.0003272] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/14/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Cryptococcosis due to Cryptococcus gattii is endemic in various parts of the world, affecting mostly immunocompetent patients. A national surveillance study of cryptococcosis, including demographical, clinical and microbiological data, has been ongoing since 1997 in Colombia, to provide insights into the epidemiology of this mycosis. METHODOLOGY/PRINCIPAL FINDINGS From 1,209 surveys analyzed between 1997-2011, 45 cases caused by C. gattii were reported (prevalence 3.7%; annual incidence 0.07 cases/million inhabitants/year). Norte de Santander had the highest incidence (0.81 cases/million/year), representing 33.3% of all cases. The male: female ratio was 3.3∶1. Mean age at diagnosis was 41±16 years. No specific risk factors were identified in 91.1% of patients. HIV infection was reported in 6.7% of patients, autoimmune disease and steroids use in 2.2%. Clinical features included headache (80.5%), nausea/vomiting (56.1%) and neurological derangements (48.8%). Chest radiographs were taken in 21 (46.7%) cases, with abnormal findings in 7 (33.3%). Cranial CT scans were obtained in 15 (33.3%) cases, with abnormalities detected in 10 (66.7%). Treatment was well documented in 30 cases, with most receiving amphotericin B. Direct sample examination was positive in 97.7% cases. Antigen detection was positive for all CSF specimens and for 75% of serum samples. C. gattii was recovered from CSF (93.3%) and respiratory specimens (6.6%). Serotype was determined in 42 isolates; 36 isolates were serotype B (85.7%), while 6 were C (14.3%). The breakdowns of molecular types were VGII (55.6%), VGIII (31.1%) and VGI (13.3%). Among 44 strains, 16 MLST sequence types (ST) were identified, 11 of them newly reported. CONCLUSIONS/SIGNIFICANCE The results of this passive surveillance study demonstrate that cryptococcosis caused by C. gattii has a low prevalence in Colombia, with the exception of Norte de Santander. The predominance of molecular type VGII is of concern considering its association with high virulence and the potential to evolve into outbreaks.
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Affiliation(s)
- Jairo Lizarazo
- Internal Medicine Department, Hospital Universitario Erasmo Meoz, Cúcuta, Norte de Santander, Colombia
| | | | | | - Carolina Firacative
- Microbiology Group, Instituto Nacional de Salud, Bogotá, Colombia
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School – Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School – Westmead Hospital, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Millennium Institute, Sydney, Australia
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Abstract
Cryptococcus gattii is a basidiomycetous human fungal pathogen that typically causes infection in tropical and subtropical regions and is responsible for an ongoing outbreak in immunocompetent individuals on Vancouver Island and in the Pacific Northwest of the US. Pathogenesis of this species may be linked to its sexual cycle that generates infectious propagules called basidiospores. A marked predominance of only one mating type (α) in clinical and environmental isolates suggests that a-α opposite-sex reproduction may be infrequent or geographically restricted, raising the possibility of an alternative unisexual cycle involving cells of only α mating type, as discovered previously in the related pathogenic species Cryptococcus neoformans. Here we report observation of hallmark features of unisexual reproduction in a clinical isolate of C. gattii (isolate 97/433) and describe genetic and environmental factors conducive to this sexual cycle. Our results are consistent with population genetic evidence of recombination in the largely unisexual populations of C. gattii and provide a useful genetic model for understanding how novel modes of sexual reproduction may contribute to evolution and virulence in this species.
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22
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Springer DJ, Billmyre RB, Filler EE, Voelz K, Pursall R, Mieczkowski PA, Larsen RA, Dietrich FS, May RC, Filler SG, Heitman J. Cryptococcus gattii VGIII isolates causing infections in HIV/AIDS patients in Southern California: identification of the local environmental source as arboreal. PLoS Pathog 2014; 10:e1004285. [PMID: 25144534 PMCID: PMC4140843 DOI: 10.1371/journal.ppat.1004285] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 06/16/2014] [Indexed: 12/30/2022] Open
Abstract
Ongoing Cryptococcus gattii outbreaks in the Western United States and Canada illustrate the impact of environmental reservoirs and both clonal and recombining propagation in driving emergence and expansion of microbial pathogens. C. gattii comprises four distinct molecular types: VGI, VGII, VGIII, and VGIV, with no evidence of nuclear genetic exchange, indicating these represent distinct species. C. gattii VGII isolates are causing the Pacific Northwest outbreak, whereas VGIII isolates frequently infect HIV/AIDS patients in Southern California. VGI, VGII, and VGIII have been isolated from patients and animals in the Western US, suggesting these molecular types occur in the environment. However, only two environmental isolates of C. gattii have ever been reported from California: CBS7750 (VGII) and WM161 (VGIII). The incongruence of frequent clinical presence and uncommon environmental isolation suggests an unknown C. gattii reservoir in California. Here we report frequent isolation of C. gattii VGIII MATα and MATa isolates and infrequent isolation of VGI MATα from environmental sources in Southern California. VGIII isolates were obtained from soil debris associated with tree species not previously reported as hosts from sites near residences of infected patients. These isolates are fertile under laboratory conditions, produce abundant spores, and are part of both locally and more distantly recombining populations. MLST and whole genome sequence analysis provide compelling evidence that these environmental isolates are the source of human infections. Isolates displayed wide-ranging virulence in macrophage and animal models. When clinical and environmental isolates with indistinguishable MLST profiles were compared, environmental isolates were less virulent. Taken together, our studies reveal an environmental source and risk of C. gattii to HIV/AIDS patients with implications for the >1,000,000 cryptococcal infections occurring annually for which the causative isolate is rarely assigned species status. Thus, the C. gattii global health burden could be more substantial than currently appreciated. The environmentally-acquired human pathogen C. gattii is responsible for ongoing and expanding outbreaks in the Western United States and Canada. C. gattii comprises four distinct molecular types: VGI, VGII, VGIII, and VGIV. Molecular types VGI, VGII, and VGIII have been isolated from patients and animals throughout the Western US. The Pacific Northwest and Canadian outbreak is primarily caused by C. gattii VGII. VGIII is responsible for ongoing infections in HIV/AIDS patients in Southern California. However, only two environmental C. gattii isolates have ever been identified from the Californian environment: CBS7750 (VGII) and WM161 (VGIII). We sought to collect environmental samples from areas that had confirmed reports of clinical or veterinary infections. Here we report the isolation of C. gattii VGI and VGIII from environmental soil and tree samples. C. gattii isolates were obtained from three novel tree species: Canary Island pine, American sweetgum, and a Pohutukawa tree. Genetic analysis provides robust evidence that these environmental isolates are the source of human infections.
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Affiliation(s)
- Deborah J. Springer
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail: (DJS); (JH)
| | - R. Blake Billmyre
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Elan E. Filler
- David Geffen School of Medicine at UCLA, Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Los Angeles, California, United States of America
| | - Kerstin Voelz
- Institute of Microbiology & Infection and the School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- National Institute of Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital, Birmingham, United Kingdom
| | - Rhiannon Pursall
- Institute of Microbiology & Infection and the School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Piotr A. Mieczkowski
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Robert A. Larsen
- Division of Infectious Diseases, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Fred S. Dietrich
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Robin C. May
- Institute of Microbiology & Infection and the School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- National Institute of Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital, Birmingham, United Kingdom
| | - Scott G. Filler
- David Geffen School of Medicine at UCLA, Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Los Angeles, California, United States of America
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail: (DJS); (JH)
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Harris JR, Lockhart SR, Sondermeyer G, Vugia DJ, Crist MB, D'Angelo MT, Sellers B, Franco-Paredes C, Makvandi M, Smelser C, Greene J, Stanek D, Signs K, Nett RJ, Chiller T, Park BJ. Cryptococcus gattii infections in multiple states outside the US Pacific Northwest. Emerg Infect Dis 2014; 19:1620-6. [PMID: 24050410 PMCID: PMC3810751 DOI: 10.3201/eid1910.130441] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Clonal VGII subtypes (outbreak strains) of Cryptococcus gattii have caused an outbreak in the US Pacific Northwest since 2004. Outbreak-associated infections occur equally in male and female patients (median age 56 years) and usually cause pulmonary disease in persons with underlying medical conditions. Since 2009, a total of 25 C. gattii infections, 23 (92%) caused by non-outbreak strain C. gattii, have been reported from 8 non-Pacific Northwest states. Sixteen (64%) patients were previously healthy, and 21 (84%) were male; median age was 43 years (range 15-83 years). Ten patients who provided information reported no past-year travel to areas where C. gattii is known to be endemic. Nineteen (76%) patients had central nervous system infections; 6 (24%) died. C. gattii infection in persons without exposure to known disease-endemic areas suggests possible endemicity in the United States outside the outbreak-affected region; these infections appear to differ in clinical and demographic characteristics from outbreak-associated C. gattii. Clinicians outside the outbreak-affected areas should be aware of locally acquired C. gattii infection and its varied signs and symptoms.
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Morais MI, Pinto MEA, Araújo SG, Castro AHF, Duarte-Almeida JM, Rosa LH, Rosa CA, Johann S, Lima LARDS. Antioxidant and antifungal activities ofSmilax campestrisGriseb. (Smilacaceae). Nat Prod Res 2014; 28:1275-9. [DOI: 10.1080/14786419.2014.895728] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Souza MA, Johann S, Lima LARDS, Campos FF, Mendes IC, Beraldo H, Souza-Fagundes EMD, Cisalpino PS, Rosa CA, Alves TMDA, de Sá NP, Zani CL. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives. Mem Inst Oswaldo Cruz 2014; 108:S0074-02762013000300342. [PMID: 23778660 DOI: 10.1590/s0074-02762013000300013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/19/2012] [Indexed: 01/27/2023] Open
Abstract
Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.
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Affiliation(s)
- Marina Azevêdo Souza
- Fiocruz, Centro de Pesquisas René Rachou, Laboratório de Química de Produtos Naturais, Belo Horizonte, MG, Brasil
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26
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Harris JR, Galanis E, Lockhart SR. Cryptococcus gattii Infections and Virulence. CURRENT FUNGAL INFECTION REPORTS 2014. [DOI: 10.1007/s12281-013-0170-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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27
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Lockhart SR, Iqbal N, Harris JR, Grossman NT, DeBess E, Wohrle R, Marsden-Haug N, Vugia DJ. Cryptococcus gattii in the United States: genotypic diversity of human and veterinary isolates. PLoS One 2013; 8:e74737. [PMID: 24019979 PMCID: PMC3760847 DOI: 10.1371/journal.pone.0074737] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/06/2013] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Cryptococcusgattii infections are being reported in the United States (US) with increasing frequency. Initially, US reports were primarily associated with an ongoing C. gattii outbreak in the Pacific Northwest (PNW) states of Washington and Oregon, starting in 2004. However, reports of C. gattii infections in patients from other US states have been increasing since 2009. Whether this is due to increasing frequency of disease, greater recognition within the clinical community, or both is currently unknown. METHODOLOGY/PRINCIPAL FINDINGS During 2005-2013, a total of 273 C. gattii isolates from human and veterinary sources in 16 US states were collected. Of these, 214 (78%) were from the Pacific Northwest (PNW) and comprised primarily the clonal C. gattii genotypes VGIIa (64%), VGIIc (21%) and VGIIb (9%). The 59 isolates from outside the PNW were predominantly molecular types VGIII (44%) and VGI (41%). Genotyping using multilocus sequence typing revealed small clusters, including a cluster of VGI isolates from the southeastern US, and an unrelated cluster of VGI isolates and a large cluster of VGIII isolates from California. Most of the isolates were mating type MATα, including all of the VGII isolates, but one VGI and three VGIII isolates were mating type MATa. CONCLUSIONS/SIGNIFICANCE We provide the most comprehensive report to date of genotypic diversity of US C. gattii isolates both inside and outside of the PNW. C. gattii may have multiple endemic regions in the US, including a previously-unrecognized endemic region in the southeast. Regional clusters exist both in California and the Southeastern US. VGII strains associated with the PNW outbreak do not appear to have spread substantially beyond the PNW.
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Affiliation(s)
- Shawn R. Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Naureen Iqbal
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Julie R. Harris
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Nina T. Grossman
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Emilio DeBess
- Oregon Department of Human Services, Portland, Oregon, United States of America
| | - Ron Wohrle
- 3 Washington State Department of Health, Tumwater, Washington, United States of America
| | - Nicola Marsden-Haug
- 3 Washington State Department of Health, Tumwater, Washington, United States of America
| | - Duc J. Vugia
- California Department of Public Health, Richmond, California, United States of America
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28
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Khayhan K, Hagen F, Pan W, Simwami S, Fisher MC, Wahyuningsih R, Chakrabarti A, Chowdhary A, Ikeda R, Taj-Aldeen SJ, Khan Z, Ip M, Imran D, Sjam R, Sriburee P, Liao W, Chaicumpar K, Vuddhakul V, Meyer W, Trilles L, van Iersel LJJ, Meis JF, Klaassen CHW, Boekhout T. Geographically structured populations of Cryptococcus neoformans Variety grubii in Asia correlate with HIV status and show a clonal population structure. PLoS One 2013; 8:e72222. [PMID: 24019866 PMCID: PMC3760895 DOI: 10.1371/journal.pone.0072222] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 07/08/2013] [Indexed: 12/29/2022] Open
Abstract
Cryptococcosis is an important fungal disease in Asia with an estimated 140,000 new infections annually the majority of which occurs in patients suffering from HIV/AIDS. Cryptococcus neoformans variety grubii (serotype A) is the major causative agent of this disease. In the present study, multilocus sequence typing (MLST) using the ISHAM MLST consensus scheme for the C. neoformans/C. gattii species complex was used to analyse nucleotide polymorphisms among 476 isolates of this pathogen obtained from 8 Asian countries. Population genetic analysis showed that the Asian C. neoformans var. grubii population shows limited genetic diversity and demonstrates a largely clonal mode of reproduction when compared with the global MLST dataset. HIV-status, sequence types and geography were found to be confounded. However, a correlation between sequence types and isolates from HIV-negative patients was observed among the Asian isolates. Observations of high gene flow between the Middle Eastern and the Southeastern Asian populations suggest that immigrant workers in the Middle East were originally infected in Southeastern Asia.
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Affiliation(s)
- Kantarawee Khayhan
- Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand
- CBS-KNAW Fungal Biodiversity Centre, Department of Yeast and Basidiomycete Research, Utrecht, The Netherlands
- Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Ferry Hagen
- CBS-KNAW Fungal Biodiversity Centre, Department of Yeast and Basidiomycete Research, Utrecht, The Netherlands
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Weihua Pan
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Institute of Dermatology and Medical Mycology, Changzheng Hospital, Secondary Military Medical University, Shanghai, People's Republic of China
| | - Sitali Simwami
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Matthew C. Fisher
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Retno Wahyuningsih
- Division of Mycology, Department of Parasitology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Christian University of Indonesia, Jakarta, Indonesia
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Reiko Ikeda
- Department of Microbiology, Meiji Pharmaceutical University, Tokyo, Japan
| | - Saad J. Taj-Aldeen
- Mycology Unit, Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Ziauddin Khan
- Department of Microbiology, Faculty of Medicine, Health Sciences Centre, Kuwait University, Jabriya, Kuwait
| | - Margaret Ip
- Department of Microbiology, Chinese University of Hong Kong, Hong Kong
| | - Darma Imran
- Department of Neurology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
- Department of Neurology, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Ridhawati Sjam
- Division of Mycology, Department of Parasitology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Pojana Sriburee
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wanqing Liao
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Institute of Dermatology and Medical Mycology, Changzheng Hospital, Secondary Military Medical University, Shanghai, People's Republic of China
| | - Kunyaluk Chaicumpar
- Research and Diagnostic Center for Emerging Infectious Disease, and Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Varaporn Vuddhakul
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai , Thailand
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Sydney Medical School–Westmead, The University of Sydney, Westmead Hospital, Sydney, Australia
| | - Luciana Trilles
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Sydney Medical School–Westmead, The University of Sydney, Westmead Hospital, Sydney, Australia
- Laboratório de Micologia, Instituto de Pesquisa Clínica Evandro Chagas, Fundacao Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Corné H. W. Klaassen
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Teun Boekhout
- CBS-KNAW Fungal Biodiversity Centre, Department of Yeast and Basidiomycete Research, Utrecht, The Netherlands
- Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Institute of Dermatology and Medical Mycology, Changzheng Hospital, Secondary Military Medical University, Shanghai, People's Republic of China
- * E-mail:
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Springer DJ, Saini D, Byrnes EJ, Heitman J, Frothingham R. Development of an aerosol model of Cryptococcus reveals humidity as an important factor affecting the viability of Cryptococcus during aerosolization. PLoS One 2013; 8:e69804. [PMID: 23894542 PMCID: PMC3720958 DOI: 10.1371/journal.pone.0069804] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/12/2013] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus is an emerging global health threat that is annually responsible for over 1,000,000 infections and one third of all AIDS patient deaths. There is an ongoing outbreak of cryptococcosis in the western United States and Canada. Cryptococcosis is a disease resulting from the inhalation of the infectious propagules from the environment. The current and most frequently used animal infection models initiate infection via liquid suspension through intranasal instillation or intravenous injection. These models do not replicate the typically dry nature of aerosol exposure and may hinder our ability to decipher the initial events that lead to clearance or the establishment of infection. We have established a standardized aerosol model of murine infection for the human fungal pathogen Cryptococcus. Aerosolized cells were generated utilizing a Collison nebulizer in a whole-body Madison Chamber at different humidity conditions. The aerosols inside the chamber were sampled using a BioSampler to determine viable aerosol concentration and spray factor (ratio of viable aerosol concentration to total inoculum concentration). We have effectively delivered yeast and yeast-spore mixtures to the lungs of mice and observed the establishment of disease. We observed that growth conditions prior to exposure and humidity within the Madison Chamber during exposure can alter Cryptococcus survival and dose retained in mice.
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Affiliation(s)
- Deborah J Springer
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.
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New Insights into HIV/AIDS-Associated Cryptococcosis. ISRN AIDS 2013; 2013:471363. [PMID: 24052889 PMCID: PMC3767198 DOI: 10.1155/2013/471363] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 01/10/2013] [Indexed: 12/27/2022]
Abstract
Cryptococcal meningitis is a life-threatening opportunistic fungal infection in both HIV-infected and HIV-uninfected patients. According to the most recent taxonomy, the responsible fungus is classified into a complex that contains two species (Cryptococcus neoformans and C. gattii), with eight major molecular types. HIV infection is recognized worldwide as the main underlying disease responsible for the development of cryptococcal meningitis (accounting for 80-90% of cases). In several areas of sub-Saharan Africa with the highest HIV prevalence despite the recent expansion of antiretroviral (ARV) therapy programme, cryptococcal meningitis is the leading cause of community-acquired meningitis with a high mortality burden. Although cryptococcal meningitis should be considered a neglected disease, a large body of knowledge has been developed by several studies performed in recent years. This paper will focus especially on new clinical aspects such as immune reconstitution inflammatory syndrome, advances on management, and strategies for the prevention of clinical disease.
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Altered immune response differentially enhances susceptibility to Cryptococcus neoformans and Cryptococcus gattii infection in mice expressing the HIV-1 transgene. Infect Immun 2013; 81:1100-13. [PMID: 23340313 DOI: 10.1128/iai.01339-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cryptococcus neoformans var. grubii is the most frequent cause of AIDS-associated cryptococcosis worldwide, while Cryptococcus gattii usually infects immunocompetent people. To understand the mechanisms which cause differential susceptibility to these cryptococcal species in HIV infection, we established and characterized a model of cryptococcosis in CD4C/HIV(MutA) transgenic (Tg) mice expressing gene products of HIV-1 and developing an AIDS-like disease. Tg mice infected intranasally with C. neoformans var. grubii strain H99 or C23 consistently displayed reduced survival compared to non-Tg mice at three graded inocula, while shortened survival of Tg mice infected with C. gattii strain R265 or R272 was restricted to a single high inoculum. HIV-1 transgene expression selectively augmented systemic dissemination to the liver and spleen for strains H99 and C23 but not strains R265 and R272. Histopathologic examination of lungs of Tg mice revealed large numbers of widely scattered H99 cells, with a minimal inflammatory cell response, while in the non-Tg mice H99 was almost completely embedded within extensive mixed inflammatory cell infiltrates. In contrast to H99, R265 was dispersed throughout the lung parenchyma and failed to induce a strong inflammatory response in both Tg and non-Tg mice. HIV-1 transgene expression reduced pulmonary production of CCL2 and CCL5 after infection with H99 or R265, and production of these two chemokines was lower after infection with R265. These results indicate that an altered immune response in these Tg mice markedly enhances C. neoformans but not C. gattii infection. This model therefore provides a powerful new tool to further investigate the immunopathogenesis of cryptococcosis.
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Springer DJ, Phadke S, Billmyre B, Heitman J. Cryptococcus gattii, no longer an accidental pathogen? CURRENT FUNGAL INFECTION REPORTS 2012; 6:245-256. [PMID: 23243480 DOI: 10.1007/s12281-012-0111-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cryptococcus gattii is an environmentally occurring pathogen that is responsible for causing cryptococcosis marked by pneumonia and meningoencephalitis in humans and animals. C. gattii can form long-term associations with trees and soil resulting in the production of infectious propagules (spores and desiccated yeast). The ever expanding reports of clinical and environmental isolation of C. gattii in temperate climates strongly imply C. gattii occurs world-wide. The key ability of yeast and spores to enter, survive, multiply, and exit host cells and to infect immunocompetent hosts distinguishes C. gattii as a primary pathogen and suggest evolution of C. gattii pathogenesis as a result of interaction with plants and other organisms in its environmental niche. Here we summarize the historical literature on C. gattii and recent literature supporting the world-wide occurrence of the primary pathogen C. gattii.
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Affiliation(s)
- Deborah J Springer
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
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Nigam C, Gahlot R, Kumar V, Chakravarty J, Tilak R. Central Nervous System Cryptococcosis among a Cohort of HIV Infected Patients from a University Hospital of North India. J Clin Diagn Res 2012; 6:1385-7. [PMID: 23205353 PMCID: PMC3471506 DOI: 10.7860/jcdr/2012/4158.2365] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 06/28/2012] [Indexed: 11/24/2022]
Abstract
BACKGROUND Cryptococcus neoformans is a ubiquitous encapsulated yeast that causes significant infections which range from asymptomatic pulmonary colonization to the life threatening meningoencephalitis, especially in immunocompromised individuals. Cryptococcal meningitis is one of the AIDS-defining illnesses. Recent data have indicated that, the incidence of the cryptococcal infection is high in developing countries like India. We conducted this study to find out the incidence of cryptococcosis in this area. MATERIAL AND METHODS The Cerebrospinal Fluid (CSF) specimens were collected from known HIV positive cases that had a clinical diagnosis of meningitis and they were processed by standard microbiological procedures. The cryptococcal isolates were identified by microscopy, their cultural characteristics, sugar assimilation and by the hydrolysis of urea. RESULTS The incidence of cryptococcal meningitis was 12.9%. All the strains were susceptible to amphotericin B, fluconazole, itraconazole and voriconazole. CONCLUSION The cryptococcal infection should be suspected in all cases of meningitis, especially among HIV infected persons. An early diagnosis and treatment may alter the prognosis of these patients and hence, an examination of the CSF for cryptococcosis should be considered in all the HIV infected persons who have the symptoms of meningitis.
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Affiliation(s)
- Chaitanya Nigam
- Service Senior Resident, Department of Microbiology, IMS, BHU, Varanasi, India
| | - Rupam Gahlot
- Junior Resident, Department of Microbiology, IMS, BHU, Varanasi, India
| | - Vikas Kumar
- Service Senior Resident, Department of Microbiology, IMS, BHU, Varanasi, India
| | - Jaya Chakravarty
- Assistant Professor, Department of Medicine, IMS, BHU, Varanasi, India
| | - Ragini Tilak
- Associate Professor, Department of Microbiology, IMS, BHU, Varanasi, India
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Hejchman E, Ostrowska K, Maciejewska D, Kossakowski J, Courchesne WE. Synthesis and antifungal activity of derivatives of 2- and 3-benzofurancarboxylic acids. J Pharmacol Exp Ther 2012; 343:380-8. [PMID: 22892340 DOI: 10.1124/jpet.112.196980] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We found that amiodarone has potent antifungal activity against a broad range of fungi, potentially defining a new class of antimycotics. Investigations into its molecular mechanisms showed amiodarone mobilized intracellular Ca2+, which is thought to be an important antifungal characteristic of its fungicidal activity. Amiodarone is a synthetic drug based on the benzofuran ring system, which is contained in numerous compounds that are both synthetic and isolated from natural sources with antifungal activity. To define the structural components responsible for antifungal activity, we synthesized a series of benzofuran derivatives and tested them for the inhibition of growth of two pathogenic fungi, Cryptococcus neoformans and Aspergillus fumigatus, to find new compounds with antifungal activity. We found several derivatives that inhibited fungal growth, two of which had significant antifungal activity. We were surprised to find that calcium fluxes in cells treated with these derivatives did not correlate directly with their antifungal effects; however, the derivatives did augment the amiodarone-elicited calcium flux into the cytoplasm. We conclude that antifungal activity of these new compounds includes changes in cytoplasmic calcium concentration. Analyses of these benzofuran derivatives suggest that certain structural features are important for antifungal activity. Antifungal activity drastically increased on converting methyl 7-acetyl-6-hydroxy-3-methyl-2-benzofurancarboxylate (2b) into its dibromo derivative, methyl 7-acetyl-5-bromo-6-hydroxy-3-bromomethyl-2-benzofurancarboxylate (4).
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Affiliation(s)
- Elzbieta Hejchman
- Department of Organic Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland
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Albuquerque PC, Rodrigues ML. Research trends on pathogenic Cryptococcus species in the last 20 years: a global analysis with focus on Brazil. Future Microbiol 2012; 7:319-29. [PMID: 22393887 DOI: 10.2217/fmb.11.162] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
AIMS Recent data demonstrates that cryptococcosis caused by Cryptococcus neoformans or Cryptococcus gattii kills approximately 600,000 people per year in the world. In Brazil, cryptococcosis has recently been identified as the most fatal mycosis in AIDS patients. In this study, we aimed to map research into C. neoformans and C. gattii in the world, with a focus on the Brazilian contribution to this area. METHODS The parameters used for this analysis were based on publication records, including number of articles published, citation indices, journal impact factor and distribution of authorship in the last two decades. RESULTS Our global analysis of publications demonstrated that, in the last 20 years, the USA was the country that produced the highest number of scientific articles in the Cryptococcus field, while Brazil occupied the third position. Brazilian productivity, however, showed a steady tendency to increase, in contrast to the USA and other countries. The average impact factor of journals at which articles authored by Brazilians were published was 2.58, which represented approximately half the value found for papers of American authorship. Studies authored by Brazilian scientists showed relatively low averages of citations per article, in comparison to papers published by researchers from the USA, France, Australia, The Netherlands and Germany, among others. CONCLUSION This study demonstrates that the contribution of Brazilian scientists to the Cryptococcus field is continually growing, although papers produced in Brazil apparently have poor repercussion in comparison to those generated in developed countries.
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Affiliation(s)
- Priscila C Albuquerque
- Laboratório de Estudos Integrados em Bioquímica Microbiana, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, 21941-902, Brazil
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Chaturvedi V, Nierman WC. Cryptococcus gattii comparative genomics and transcriptomics: a NIH/NIAID White Paper. Mycopathologia 2011; 173:367-73. [PMID: 22179781 DOI: 10.1007/s11046-011-9512-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 11/29/2011] [Indexed: 01/12/2023]
Abstract
Cryptococcus gattii is an emerging global pathogen. Recent reports suggest that C. gattii cryptococcosis is more common in immunocompetent as well as HIV-infected AIDS patients than earlier estimated. An ongoing outbreak of C. gattii in Vancouver, Canada, and the US Pacific Northwest has heightened public health awareness in North America. We have few clues as to what causes emergence or re-emergence of highly pathogenic strains, why C. gattii split up from its sibling pathogen C. neoformans, why it thrives in trees instead, and why immunocompetent individuals are vulnerable to this pathogen? C. gattii comprises of four distinct lineages, but the information on the genome of C. gattii is inadequate and unrepresentative as it is limited to two strains, R265 and WM276, which are MATα, serotype B, genotype VGII/VGI from Canada and Australia, respectively. There is a wide gap in knowledge about the genomes of VGIII and VGIV strains, serotype C strains, and MATa strains. The geographical representation is inadequate in the absence of strains from California, South America, Asia, and Africa. Additional obstacles to work with this pathogen are the following: (a) complex molecular typing schemes and (b) lack of functional genomics analyses. We propose to complete genome sequencing of 12 reference strains by next-generation sequencing technology and to map their transcriptomes by RNA-Seq technology. This effort would lead to new resources for the scientific community including (1) insight from additional C. gattii genomes to anchor future research studies, (2) validation of single-nucleotide polymorphisms (SNPs) for molecular typing to improve epidemiology studies, and (3) transcript analyses from strains under relevant pathogenic and non-pathogenic conditions to accelerate the discovery of proteins for diagnostics, drug targets, and vaccines.
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Affiliation(s)
- V Chaturvedi
- New York State Department of Health, Wadsworth Center, Albany, NY, USA.
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Walraven CJ, Gerstein W, Hardison SE, Wormley F, Lockhart SR, Harris JR, Fothergill A, Wickes B, Gober-Wilcox J, Massie L, Ku TSN, Firacative C, Meyer W, Lee SA. Fatal disseminated Cryptococcus gattii infection in New Mexico. PLoS One 2011; 6:e28625. [PMID: 22194869 PMCID: PMC3237461 DOI: 10.1371/journal.pone.0028625] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 11/11/2011] [Indexed: 01/15/2023] Open
Abstract
We report a case of fatal disseminated infection with Cryptococcus gattii in a patient from New Mexico. The patient had no history of recent travel to known C. gattii-endemic areas. Multilocus sequence typing revealed that the isolate belonged to the major molecular type VGIII. Virulence studies in a mouse pulmonary model of infection demonstrated that the strain was less virulent than other C. gattii strains. This represents the first documented case of C. gattii likely acquired in New Mexico.
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Affiliation(s)
- Carla J. Walraven
- Section of Infectious Diseases, New Mexico Veterans Healthcare System, Albuquerque, New Mexico, United States of America
- Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, United States of America
| | - Wendy Gerstein
- Section of Infectious Diseases, New Mexico Veterans Healthcare System, Albuquerque, New Mexico, United States of America
- Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, United States of America
| | - Sarah E. Hardison
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Floyd Wormley
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Shawn R. Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Julie R. Harris
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Annette Fothergill
- Department of Microbiology and Immunology, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Brian Wickes
- Department of Microbiology and Immunology, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Julie Gober-Wilcox
- Section of Infectious Diseases, New Mexico Veterans Healthcare System, Albuquerque, New Mexico, United States of America
| | - Larry Massie
- Section of Infectious Diseases, New Mexico Veterans Healthcare System, Albuquerque, New Mexico, United States of America
| | - T. S. Neil Ku
- Section of Infectious Diseases, New Mexico Veterans Healthcare System, Albuquerque, New Mexico, United States of America
- Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, United States of America
| | - Carolina Firacative
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Sydney Medical School - Westmead Hospital, The University of Sydney, New South Wales, Australia
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Sydney Medical School - Westmead Hospital, The University of Sydney, New South Wales, Australia
| | - Samuel A. Lee
- Section of Infectious Diseases, New Mexico Veterans Healthcare System, Albuquerque, New Mexico, United States of America
- Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, United States of America
- * E-mail:
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Mora DJ, da Cunha Colombo ER, Ferreira-Paim K, Andrade-Silva LE, Nascentes GAN, Silva-Vergara ML. Clinical, epidemiological and outcome features of patients with cryptococcosis in Uberaba, Minas Gerais, Brazil. Mycopathologia 2011; 173:321-7. [PMID: 22130645 DOI: 10.1007/s11046-011-9504-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 11/02/2011] [Indexed: 11/24/2022]
Abstract
Nearly one million of cryptococcosis cases occur yearly around the world, involving mainly HIV-infected patients who are not receiving antiretroviral therapy (ART) or present poor adherence. This study aims to evaluate epidemiological, clinical and outcome aspects of patients with cryptococcosis from 1998-2010. Patients were prospectively recruited, and their medical and laboratory records were reviewed. A total of 131 cases were included, and of these, 119 (90.83%) had AIDS, 4 received a renal transplant, 2 presented systemic lupus erythematosus and 6 (4.6%) were apparently immunocompetent. Ninety-one (69.46%) were men, and the median age was 38.7 years. Cryptococcal meningitis (CM) was diagnosed in 103 (78.62%), whereas 28 (21.38%) had cryptococcal infection in other sites. Of patients with CM, 94 (91.26%) had AIDS being cryptococcosis the first defining illness in 61 (64.9%), while 37 (60.65%) of them presented simultaneously both diagnosis. Headache, altered mental status, papilledema and seizures at admission were significatively associated with a poor outcome. Of 163 different isolates, 155 (95.09%) were Cryptococcus neoformans and eight (4.88%) Cryptococcus gattii. Antifungal therapy was warranted in 8 (87.4%) patients with CM, but 46 (51.1%) died during the first days or weeks. Of 28 patients without CM, 21 (75%) received treatment, but 6 (28.6%) died. The poor outcome among this case series was similar to that reported from other developing countries, but it is paradoxal in Brazil where the ART is at free disposal in the public health services. Despite, at least 60-70% of patients present advanced immunosuppression when they receive the AIDS diagnosis.
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Affiliation(s)
- Delio José Mora
- Infectious Diseases Department, Triângulo Mineiro Federal University, Uberaba, Minas Gerais, Brazil
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Debourgogne A, Iriart X, Blanchet D, Veron V, Boukhari R, Nacher M, Carme B, Aznar C. Characteristics and specificities of Cryptococcus infections in French Guiana, 1998–2008. Med Mycol 2011; 49:864-71. [DOI: 10.3109/13693786.2011.584198] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Harris JR, Lockhart SR, Debess E, Marsden-Haug N, Goldoft M, Wohrle R, Lee S, Smelser C, Park B, Chiller T. Cryptococcus gattii in the United States: clinical aspects of infection with an emerging pathogen. Clin Infect Dis 2011; 53:1188-95. [PMID: 22016503 DOI: 10.1093/cid/cir723] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Cryptococcus gattii (Cg) has caused increasing infections in the US Pacific Northwest (PNW) since 2004. We describe this outbreak and compare clinical aspects of infection in the United States among patients infected with different Cg genotypes. METHODS Beginning in 2005, PNW state health departments conducted retrospective and prospective passive surveillance for Cg infections, including patient interviews and chart reviews; clinical isolates were genotyped at the US Centers for Disease Control and Prevention (CDC). We examined symptom frequency and underlying conditions in US patients with Cg infection and modeled factors associated with death. RESULTS From 1 December 2004 to July 2011, 96 Cg infections were reported to the CDC. Eighty-three were in patients in or travelers to the PNW, 78 of which were genotypes VGIIa, VGIIb, or VGIIc (outbreak strains). Eighteen patients in and outside the PNW had other molecular type Cg infections (nonoutbreak strains). Patients with outbreak strain infections were more likely than those with nonoutbreak-strain infections to have preexisting conditions (86% vs 31%, respectively; P < .0001) and respiratory symptoms (75% vs 36%, respectively; P = .03) and less likely to have central nervous system (CNS) symptoms (37% vs 90%, respectively; P = .008). Preexisting conditions were associated with increased pneumonia risk and decreased risk of meningitis and CNS symptoms. Nineteen (33%) of 57 patients died. Past-year oral steroid use increased odds of death in multivariate analysis (P = .05). CONCLUSIONS Clinical differences may exist between outbreak-strain (VGIIa, VGIIb, and VGIIc) and nonoutbreak-strain Cg infections in the United States. Clinicians should have a low threshold for testing for Cg, particularly among patients with recent travel to the PNW.
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Affiliation(s)
- J R Harris
- Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Byrnes EJ, Bartlett KH, Perfect JR, Heitman J. Cryptococcus gattii: an emerging fungal pathogen infecting humans and animals. Microbes Infect 2011; 13:895-907. [PMID: 21684347 PMCID: PMC3318971 DOI: 10.1016/j.micinf.2011.05.009] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/19/2011] [Accepted: 05/20/2011] [Indexed: 01/01/2023]
Abstract
Infectious fungi are among a broad group of microbial pathogens that has and continues to emerge concomitantly due to the global AIDS pandemic as well as an overall increase of patients with compromised immune systems. In addition, many pathogens have been emerging and re-emerging, causing disease in both individuals who have an identifiable immune defect and those who do not. The fungal pathogen Cryptococcus gattii can infect individuals with and without an identifiable immune defect, with a broad geographic range including both endemic areas and emerging outbreak regions. Infections in patients and animals can be severe and often fatal if untreated. We review the molecular epidemiology, population structure, clinical manifestations, and ecological niche of this emerging pathogen.
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Affiliation(s)
- Edmond J. Byrnes
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Karen H. Bartlett
- School of Environmental Health, University of British Columbia, Vancouver, BC, Canada
| | - John R. Perfect
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
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42
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Abstract
Infections caused by the emerging pathogen Cryptococcus gattii are increasing in frequency in North America. During the past decade, interest in the pathogen has continued to grow, not only in North America but also in other areas of the world where infections have recently been documented. This review synthesizes existing data and raises issues that remain to be addressed.
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Affiliation(s)
- Julie Harris
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS C-09, Atlanta, GA 30309 USA.
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Byrnes EJ, Li W, Ren P, Lewit Y, Voelz K, Fraser JA, Dietrich FS, May RC, Chatuverdi S, Chatuverdi V, Heitman J. A diverse population of Cryptococcus gattii molecular type VGIII in southern Californian HIV/AIDS patients. PLoS Pathog 2011; 7:e1002205. [PMID: 21909264 PMCID: PMC3164645 DOI: 10.1371/journal.ppat.1002205] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 06/25/2011] [Indexed: 11/18/2022] Open
Abstract
Cryptococcus gattii infections in southern California have been reported in patients with HIV/AIDS. In this study, we examined the molecular epidemiology, population structure, and virulence attributes of isolates collected from HIV/AIDS patients in Los Angeles County, California. We show that these isolates consist almost exclusively of VGIII molecular type, in contrast to the VGII molecular type isolates causing the North American Pacific Northwest outbreak. The global VGIII population structure can be divided into two molecular groups, VGIIIa and VGIIIb. Isolates from the Californian patients are virulent in murine and macrophage models of infection, with VGIIIa significantly more virulent than VGIIIb. Several VGIII isolates are highly fertile and produce abundant sexual spores that may serve as infectious propagules. The a and α VGIII MAT locus alleles are largely syntenic with limited rearrangements compared to the known VGI (a/α) and VGII (α) MAT loci, but each has unique characteristics including a distinct deletion flanking the 5' VGIII MATa alleles and the α allele is more heterogeneous than the a allele. Our studies indicate that C. gattii VGIII is endemic in southern California, with other isolates originating from the neighboring regions of Mexico, and in rarer cases from Oregon and Washington state. Given that >1,000,000 cases of cryptococcal infection and >620,000 attributable mortalities occur annually in the context of the global AIDS pandemic, our findings suggest a significant burden of C. gattii may be unrecognized, with potential prognostic and therapeutic implications. These results signify the need to classify pathogenic Cryptococcus cases and highlight possible host differences among the C. gattii molecular types influencing infection of immunocompetent (VGI/VGII) vs. immunocompromised (VGIII/VGIV) hosts.
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Affiliation(s)
- Edmond J. Byrnes
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Wenjun Li
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Ping Ren
- Mycology Laboratory, Wadsworth Center, Albany, New York, United States of America
| | - Yonathan Lewit
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kerstin Voelz
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - James A. Fraser
- Centre for Infectious Disease Research, Department of Molecular and Microbial Sciences, University of Queensland, Brisbane, Australia
| | - Fred S. Dietrich
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Institute for Genome Sciences and Policy, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Robin C. May
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Sudha Chatuverdi
- Mycology Laboratory, Wadsworth Center, Albany, New York, United States of America
| | - Vishnu Chatuverdi
- Mycology Laboratory, Wadsworth Center, Albany, New York, United States of America
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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Johann S, Mendes BG, Missau FC, de Resende MA, Pizzolatti MG. Antifungal activity of five species of Polygala. Braz J Microbiol 2011; 42:1065-75. [PMID: 24031724 PMCID: PMC3768791 DOI: 10.1590/s1517-838220110003000027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 10/13/2010] [Accepted: 05/16/2011] [Indexed: 11/22/2022] Open
Abstract
Crude extracts and fractions of five species of Polygala - P. campestris, P. cyparissias, P. paniculata, P. pulchella and P. sabulosa - were investigated for their in vitro antifungal activity against opportunistic Candida species, Cryptococcus gattii and Sporothrix schenckii with bioautographic and microdilution assays. In the bioautographic assays, the major extracts were active against the fungi tested. In the minimal concentration inhibitory (MIC) assay, the hexane extract of P. paniculata and EtOAc fraction of P. sabulosa showed the best antifungal activity, with MIC values of 60 and 30 μg/mL, respectively, against C. tropicalis, C. gattii and S. schenckii. The compounds isolated from P. sabulosa prenyloxycoumarin and 1,2,3,4,5,6-hexanehexol displayed antifungal activity against S. schenckii (with MICs of 125 μg/mL and 250 μg/mL, respectively) and C. gattii (both with MICs of 250 μg/mL). Rutin and aurapten isolated from P. paniculata showed antifungal activity against C. gattii with MIC values of 60 and 250 μg/mL, respectively. In the antifungal screening, few of the isolated compounds showed good antifungal inhibition. The compound α-spinasterol showed broad activity against the species tested, while rutin had the best activity with the lowest MIC values for the microorganisms tested. These two compounds may be chemically modified by the introduction of a substitute group that would alter several physico-chemical properties of the molecule, such as hydrophobicity, electronic density and steric strain.
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Affiliation(s)
- Susana Johann
- Departamento de Microbiologia, Universidade Federal de Minas Gerais , Belo Horizonte, MG , Brasil
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Kronstad JW, Hu G, Choi J. The cAMP/Protein Kinase A Pathway and Virulence in Cryptococcus neoformans. MYCOBIOLOGY 2011; 39:143-50. [PMID: 22783095 PMCID: PMC3385117 DOI: 10.5941/myco.2011.39.3.143] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 08/30/2011] [Indexed: 05/21/2023]
Abstract
The basidiomycete fungus Cryptococcus neoformans is an important pathogen of immunocompromised people. The ability of the fungus to sense its environment is critical for proliferation and the generation of infectious propagules, as well as for adaptation to the mammalian host during infection. The conserved cAMP/protein kinase A pathway makes an important contribution to sensing, as demonstrated by the phenotypes of mutants with pathway defects. These phenotypes include loss of the ability to mate and to elaborate the key virulence factors capsule and melanin. This review summarizes recent work that reveals new targets of the pathway, new phenotypic consequences of signaling defects, and a more detailed understanding of connections with other aspects of cryptococcal biology including iron regulation, pH sensing, and stress.
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Affiliation(s)
- James W Kronstad
- The Michael Smith Laboratories, Department of Microbiology and Immunology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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Chaturvedi V, Chaturvedi S. Cryptococcus gattii: a resurgent fungal pathogen. Trends Microbiol 2011; 19:564-71. [PMID: 21880492 DOI: 10.1016/j.tim.2011.07.010] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 07/19/2011] [Accepted: 07/29/2011] [Indexed: 01/20/2023]
Abstract
Cryptococcus gattii and Cryptococcus neoformans are causal agents of cryptococcosis, which manifests as pneumonia and meningitis. C. gattii has recently received widespread attention owing to outbreaks in British Columbia, Canada and the US Pacific Northwest. The biology of this tree-dwelling yeast is relatively unexplored, and there are few clues about how it causes infections in humans and animals. In this review, we summarize recent discoveries about C. gattii genetics and its ecological niche and highlight areas ripe for future exploration. Increased focus on epidemiology, ecological modeling and host-pathogen interactions is expected to yield a better understanding of this enigmatic yeast, and ultimately lead to better measures for its control.
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Affiliation(s)
- Vishnu Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA.
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48
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The Outbreak of Cryptococcus gattii in Western North America: Epidemiology and Clinical Issues. Curr Infect Dis Rep 2011; 13:256-61. [PMID: 21461678 DOI: 10.1007/s11908-011-0181-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Over the previous decade, we observed the emergence of the fungal pathogen, Cryptococcus gattii, as a cause of disease in humans and animals in a temperate climate. This outbreak, first documented on Vancouver Island, has since expanded throughout Western North America, with non-travel-associated cases now in British Columbia, Washington, Oregon, and California. Additionally, a secondary outbreak, originating in and still restricted to Oregon, has also occurred. During the past several years, several studies detailing molecular typing, virulence, antifungal susceptibilities, epidemiology, and clinical issues have been published. These studies begin to address the complex dynamics of this novel emergence of a rare and fatal fungus, outline clinical characteristics of human cases, and also opened several new areas that should be explored in the upcoming years.
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MacDougall L, Fyfe M, Romney M, Starr M, Galanis E. Risk factors for Cryptococcus gattii infection, British Columbia, Canada. Emerg Infect Dis 2011; 17:193-9. [PMID: 21291588 PMCID: PMC3204768 DOI: 10.3201/eid1702.101020] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
To determine whether particular environmental, medical, or behavioral risk factors existed among Cryptcoccus gattii–infected persons compared with the general population, we conducted a sex-matched case−control study on a subset of case-patients in British Columbia (1999–2001). Exposures and underlying medical conditions among all case-patients (1999–2007) were also compared with results of provincial population–based surveys and studies. In case−control analyses, oral steroids (matched odds ratio [MOR] 8.11, 95% confidence interval [CI] 1.74–37.80), pneumonia (MOR 2.71, 95% CI 1.05–6.98), and other lung conditions (MOR 3.21, 95% CI 1.08–9.52) were associated with infection. In population comparisons, case-patients were more likely to be >50 years of age (p<0.001), current smokers (p<0.001), infected with HIV (p<0.001), or have a history of invasive cancer (p<0.001). Although C. gattii is commonly believed to infect persons with apparently healthy immune systems, several immunosuppressive and pulmonary conditions seem to be risk factors.
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Affiliation(s)
- Laura MacDougall
- British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada.
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50
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Abstract
This study describes the isolation of Cryptococcus neoformans and Cryptococcus gattii from patients with chronic meningitis who were admitted to 16 Malaysian hospitals, from 2003 to 2004. Of the 96 cryptococcal cases reported over the 2-year period, 74 (77.1%) patients were male and 45 (46.9%) patients were between 30 and 39 years old. Cryptococcosis was uncommon in children. A total of 57 (59.4%) and 23 (24.0%) patients were Malay and Chinese respectively. Human immunodeficiency virus infection was the major underlying disease reported in 36 (37.5%) patients. C. neoformans var. grubii (serotype A and molecular type VNI) was the predominant Cryptococcus species isolated from 88.5% of cryptococcal cases in this country. Cryptococcal cases due to C. neoformans var. grubii were reported from all the five regions in Malaysia, with the most number of cases reported from the central and northern regions. Cryptococcus gattii (all were serotype B and molecular types VGI/II) was isolated from all regions except the southern region. Compared with a study conducted prior to the AIDS era, our findings show substantial changes in the demographical characteristics of patients.
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Affiliation(s)
- S T Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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