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Chen M, Wang Y, Li Y, Hong N, Zhu X, Pan W, Liao W, Xu J, Du J, Chen J. Genotypic diversity and antifungal susceptibility of environmental isolates of Cryptococcus neoformans from the Yangtze River Delta region of East China. Med Mycol 2020; 59:653-663. [PMID: 33269400 DOI: 10.1093/mmy/myaa096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/03/2020] [Accepted: 11/11/2020] [Indexed: 12/12/2022] Open
Abstract
Although cryptococcosis is widely recognized as infection by Cryptococcus neoformans sensu lato from environmental sources, information concerning the characteristics of environmental isolates of C. neoformans s. l. and how they are related to clinical isolates is very limited, especially in East China. In this study, 61 environmental isolates of C. neoformans were recovered from pigeon (Columba livia) droppings from the Yangtze River Delta region of East China. These isolates were genotyped using the ISHAM-MLST consensus scheme and their antifungal drug susceptibilities were determined following the CLSI M27-A3 guidelines. The 61 isolates were found belonging to 13 sequence types (STs), including several novel STs such as ST254 and ST194. The dominant ST in this environmental sample was ST31, different from that of clinical strains (ST5) in this region. Azole-resistance, such as fluconazole (FLU)-resistance, was observed among our environmental C. neoformans isolates. The findings of this study expand our understanding of ecological niches, population genetic diversity, and azole-resistance characteristics of the yeast in East China. Our research lays the foundation for further comparative analysis the potential mechanisms for the observed differences between environmental and clinical populations of C. neoformans in China. LAY SUMMARY Cryptococcosis is widely recognized as infection by Cryptococcus neoformans sensu lato from environmental sources. However, there is currently limited information about the genetic diversity and antifungal susceptibility of environmental C. neoformans s. l. isolates, including how they may differ from clinical samples. In this study, we collected 61 environmental C. neoformans isolates from domestic pigeon droppings from the Yangtze River Delta region of East China. These isolates were genotyped using multi-locus sequencing. We found a high genotypic diversity in this population of C. neoformans, with several novel genotypes and a distribution of genotypes different from that of clinical strains in this region. Azole-resistance, such as fluconazole (FLU)-resistance, was observed among our environmental C. neoformans isolates. The findings of this study expand our understanding of ecological niches, genetic diversity, and azole-resistance characteristics of the yeast in East China. Our research lays the foundation for phylogenomic analysis investigating why and how disparate population structures of C. neoformans isolates formed between environmental and clinical sources in the region.
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Affiliation(s)
- Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Yan Wang
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Yingfang Li
- Department of Skin & Cosmetic Research, Shanghai Skin Diseases Hospital, Shanghai, China
| | - Nan Hong
- Department of Dermatology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Xinlin Zhu
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Weihua Pan
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Wanqing Liao
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, Canada
| | - Jingxia Du
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jianghan Chen
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
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Silva THS, Araújo CV, Santos KMDC, Alves NDS, Gomes THS, Silva AKFE, Silva NCLDS, Damasceno ECB, de Carvalho AMA, Mendes MGA, Caminha HB, Daboit TC, Ferreira TB, Andrade-Silva LE, Silva-Vergara ML, Ferreira-Paim K, Fonseca FM. Synergic effect of simvastatin in combination with amphotericin B against environmental strains of Cryptococcus neoformans from northeastern Brazil: a prospective experimental study. SAO PAULO MED J 2020; 138:40-46. [PMID: 32321104 PMCID: PMC9673851 DOI: 10.1590/1516-3180.2019.0107.r2.16092019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/16/2019] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Statins are used as cholesterol-lowering drugs and may also have direct antimicrobial effects. OBJECTIVE To evaluate synergic interactions between simvastatin and both amphotericin B and fluconazole, against environmental strains of Cryptococcus neoformans isolated from captive birds' droppings. DESIGNAND SETTING Experimental study conducted at Federal University of Piauí, Parnaíba, in collaboration with Federal University of Triângulo Mineiro, Uberaba, Brazil. METHODS Statin susceptibility tests of Cryptococcus neoformans samples were performed as prescribed in standards. Interactions of simvastatin with amphotericin and fluconazole were evaluated using the checkerboard microdilution method. Presence of these interactions was quantitatively detected through determining the fractional inhibitory concentration index (FICI). RESULTS Isolates of Cryptococcus neoformans were obtained from 30 of the 206 samples of dry bird excreta (14.5%) that were collected from pet shops and houses. Ten isolates were selected for susceptibility tests. All of them were susceptible to amphotericin and fluconazole. All presented minimum inhibitory concentration (MIC) > 128 µg/ml and, thus, were resistant in vitro to simvastatin. An in vitro synergic effect was shown through combined testing of amphotericin B and simvastatin, such that six isolates (60%) presented FICI < 0.500. Two isolates showed considerable reductions in MIC, from 1 µg/ml to 0.250 µg/ml. No synergic effect was observed through combining fluconazole and simvastatin. CONCLUSION These results demonstrate that simvastatin should be considered to be a therapeutic alternative, capable of potentiating the action of amphotericin B. However, further studies are necessary to clarify the real effect of simvastatin as an antifungal agent.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Henrique Barros Caminha
- MSc. Doctoral Student, Department of Biomedical Sciences, Universidade Federal do Piauí, Parnaíba (PI), Brazil.
| | - Tatiane Caroline Daboit
- PhD. Associate Professor, Department of Medicine, Universidade Federal do Piauí, Parnaíba (PI), Brazil.
| | - Thatiana Bragine Ferreira
- MSc. Doctoral Student, Department of Infectious and Parasitic Diseases, Universidade Federal do Triângulo Mineiro, Uberaba (MG), Brazil.
| | | | - Mario León Silva-Vergara
- PhD. Associate Professor, Department of Infectious and Parasitic Diseases, Universidade Federal do Triângulo Mineiro, Uberaba (MG), Brazil.
| | - Kennio Ferreira-Paim
- PhD. Associate Professor, Department of Microbiology, Universidade Federal do Triângulo Mineiro, Uberaba (MG), Brazil.
| | - Fernanda Machado Fonseca
- PhD. Associate Professor, Department of Biomedicine, Universidade Federal do Triângulo Mineiro, Uberaba (MG), Brazil.
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Bandalizadeh Z, Javidnia J, Hosseini SA, Moosazadeh M, Amouei A, Kermani F, Seyedmousavi S, Shokohi T. Cryptococcus and cryptococcosis in Iran during 1969-2019: A systematic review and meta-analysis. J Mycol Med 2019; 30:100917. [PMID: 31864801 DOI: 10.1016/j.mycmed.2019.100917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 10/22/2019] [Accepted: 11/26/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Limited data are available on the epidemiology and etiology of cryptococcal infections in the Middle East. We aimed to conduct the systematic review and meta-analysis to summarize the epidemiological data on prevalence of Cryptococcus species complexes in trees and their surroundings, bird guano and secretions, animals, and highlight the reported episodes of cryptococcosis in Iran. MATERIALS AND METHODS Twelve databases, including PubMed, Science Direct, Scopus, Proquest, Google Scholar, Embase, and the ISI Web of Science, as well as the national databases, from January 1969 to October 2019 were searched. Furthermore, gray literature (e.g., thesis, congress abstracts) was evaluated using Iran Doc and www.thesis. RESEARCH ac.ir. Search process was accomplished on English or Persian language articles using the following keywords: "Cryptococcus", "Cryptococcosis", "invasive fungal infection", "Humans", "Birds", "Pigeon", "Animals", "Tree", "Eucalyptus", and "Iran", both alone and in combination. RESULTS Overall 36 studies were eligible regarding Cryptococcus and cryptococcosis in Iran. The total prevalence rates of Cryptococcus species in the tree was 4.7% (95% CI: 2.3-7.8), and in bird guano was 20.4% (95% CI: 10.7-32.2). Cryptococcosis in animal, and human were 1.7% (95% CI: 0.01-5.1), and 2.8% (95% CI: 0.7v6.1), respectively. The highest prevalence of Cryptococcus in the trees (14.6%), and bird guano (89.4%) in Khorasan, animals (8.9%) in Chaharmahal and Bakhtiari, and human (4.4%) in Mazandaran provinces were reported. CONCLUSIONS Given the significant risk of Cryptococcus species for susceptible humans, mainly HIV-infected patients, it seems quite necessary to adopt concrete preventive strategies to pinpoint the environmental habitats of this yeast.
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Affiliation(s)
- Z Bandalizadeh
- Student Research Committee, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - J Javidnia
- Student Research Committee, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - S A Hosseini
- Student Research Committee, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - M Moosazadeh
- Health Science Research Center, Addiction Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - A Amouei
- Student Research Committee, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - F Kermani
- Student Research Committee, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - S Seyedmousavi
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States; Center of Expertise in Microbiology, Infection Biology, and Antimicrobial Pharmacology, Tehran, Iran; Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - T Shokohi
- Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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Abstract
We discovered a new lineage of the globally important fungal pathogen Cryptococcus gattii on the basis of analysis of six isolates collected from three locations spanning the Central Miombo Woodlands of Zambia, Africa. All isolates were from environments (middens and tree holes) that are associated with a small mammal, the African hyrax. Phylogenetic and population genetic analyses confirmed that these isolates form a distinct, deeply divergent lineage, which we name VGV. VGV comprises two subclades (A and B) that are capable of causing mild lung infection with negligible neurotropism in mice. Comparing the VGV genome to previously identified lineages of C. gattii revealed a unique suite of genes together with gene loss and inversion events. However, standard URA5 restriction fragment length polymorphism (RFLP) analysis could not distinguish between VGV and VGIV isolates. We therefore developed a new URA5 RFLP method that can reliably identify the newly described lineage. Our work highlights how sampling understudied ecological regions alongside genomic and functional characterization can broaden our understanding of the evolution and ecology of major global pathogens.IMPORTANCE Cryptococcus gattii is an environmental pathogen that causes severe systemic infection in immunocompetent individuals more often than in immunocompromised humans. Over the past 2 decades, researchers have shown that C. gattii falls within four genetically distinct major lineages. By combining field work from an understudied ecological region (the Central Miombo Woodlands of Zambia, Africa), genome sequencing and assemblies, phylogenetic and population genetic analyses, and phenotypic characterization (morphology, histopathological, drug-sensitivity, survival experiments), we discovered a hitherto unknown lineage, which we name VGV (variety gattii five). The discovery of a new lineage from an understudied ecological region has far-reaching implications for the study and understanding of fungal pathogens and diseases they cause.
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Ergin Ç, Şengül M, Aksoy L, Döğen A, Sun S, Averette AF, Cuomo CA, Seyedmousavi S, Heitman J, Ilkit M. Cryptococcus neoformans Recovered From Olive Trees ( Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages. Front Cell Infect Microbiol 2019; 9:384. [PMID: 31788454 PMCID: PMC6856141 DOI: 10.3389/fcimb.2019.00384] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/25/2019] [Indexed: 11/13/2022] Open
Abstract
Cryptococcus species are life-threatening human fungal pathogens that cause cryptococcal meningoencephalitis in both immunocompromised and healthy hosts. The natural environmental niches of Cryptococcus include pigeon (Columba livia) guano, soil, and a variety of tree species such as Eucalyptus camaldulensis, Ceratonia siliqua, Platanus orientalis, and Pinus spp. Genetic and genomic studies of extensive sample collections have provided insights into the population distribution and composition of different Cryptococcus species in geographic regions around the world. However, few such studies examined Cryptococcus in Turkey. We sampled 388 Olea europaea (olive) and 132 E. camaldulensis trees from seven locations in coastal and inland areas of the Aegean region of Anatolian Turkey in September 2016 to investigate the distribution and genetic diversity present in the natural Cryptococcus population. We isolated 84 Cryptococcus neoformans strains (83 MATα and 1 MAT a) and 3 Cryptococcus deneoformans strains (all MATα) from 87 (22.4% of surveyed) O. europaea trees; a total of 32 C. neoformans strains were isolated from 32 (24.2%) of the E. camaldulensis trees, all of which were MATα. A statistically significant difference was observed in the frequency of C. neoformans isolation between coastal and inland areas (P < 0.05). Interestingly, the MAT a C. neoformans isolate was fertile in laboratory crosses with VNI and VNB MATα tester strains and produced robust hyphae, basidia, and basidiospores, thus suggesting potential sexual reproduction in the natural population. Sequencing analyses of the URA5 gene identified at least five different genotypes among the isolates. Population genetics and genomic analyses revealed that most of the isolates in Turkey belong to the VNBII lineage of C. neoformans, which is predominantly found in southern Africa; these isolates are part of a distinct minor clade within VNBII that includes several isolates from Zambia and Brazil. Our study provides insights into the geographic distribution of different C. neoformans lineages in the Mediterranean region and highlights the need for wider geographic sampling to gain a better understanding of the natural habitats, migration, epidemiology, and evolution of this important human fungal pathogen.
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Affiliation(s)
- Çağri Ergin
- Department of Microbiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Mustafa Şengül
- Department of Microbiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Levent Aksoy
- Department of Microbiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Aylin Döğen
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Mersin, Mersin, Turkey
| | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Anna F Averette
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Seyedmojtaba Seyedmousavi
- Microbiology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Macit Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey
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6
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Pllana-Hajdari D, Cogliati M, Čičmak L, Pleško S, Mlinarić-Missoni E, Mareković I. First Isolation, Antifungal Susceptibility, and Molecular Characterization of Cryptococcus neoformans from the Environment in Croatia. J Fungi (Basel) 2019; 5:jof5040099. [PMID: 31614885 PMCID: PMC6958495 DOI: 10.3390/jof5040099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/02/2019] [Accepted: 10/10/2019] [Indexed: 12/16/2022] Open
Abstract
The purpose of this study was to investigate the presence of Cryptococcus neoformans species complex isolates from environmental sources in Croatia and to determine their molecular types and antifungal susceptibility. Swab samples of tree hollows and bird excreta in the soil beneath trees were collected. Samples included 472 (92.73%) samples obtained from tree hollows and 37 (7.27%) samples from bird excreta. Four C. neoformans species complex isolates were recovered from tree hollow swabs along the Mediterranean coast, while there were no isolates recovered from bird excreta or from the continental area. Three isolates were identified as molecular types VNI and one as VNIV. All tested antifungals showed high in vitro activity against the four isolates. This is the first report proving the presence of C. neoformans species complex in the environment of Croatia. The results of the study suggest a major risk of exposure for inhabitants living along the Croatian coast and that both VNI and VNIV molecular types can be expected in clinical cases of cryptococcosis. Susceptibility to antifungals confirmed that no resistance should be expected in patients with cryptococcosis at the present time.
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Affiliation(s)
- Donjeta Pllana-Hajdari
- Department of Molecular Microbiology, National Institute of Public Health, Prishtina 10 000, Kosovo.
| | - Massimo Cogliati
- Laboratorio di Micologia Medica, Dipartimento Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano 20133, Italy.
| | - Ljiljana Čičmak
- Department for Parasitology and Mycology, Croatian Institute for Public Health, Zagreb 10 000, Croatia.
| | - Sanja Pleško
- Department of Clinical and Molecular Microbiology, University Hospital Centre Zagreb, University of Zagreb School of Medicine, Zagreb 10 000, Croatia.
| | - Emilija Mlinarić-Missoni
- Department for Parasitology and Mycology, Croatian Institute for Public Health, Zagreb 10 000, Croatia.
| | - Ivana Mareković
- Department of Clinical and Molecular Microbiology, University Hospital Centre Zagreb, University of Zagreb School of Medicine, Zagreb 10 000, Croatia.
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Prakash A, Randhawa HS, Khan ZU, Ahmad S, Hagen F, Meis JF, Chowdhary A. Environmental distribution of Cryptococcus species and some other yeast-like fungi in India. Mycoses 2018; 61:305-313. [PMID: 29280202 DOI: 10.1111/myc.12741] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 12/18/2017] [Indexed: 11/30/2022]
Abstract
A study of environmental distribution revealed the occurrence of Cryptococcus neoformans and C. gattii in 9% and 3%, respectively, of 611 samples investigated. C. neoformans showed the highest isolation frequency from tree trunk hollows in Delhi (31%), whereas C. gattii occurred in 12% of the samples in Delhi and 5% in Rajasthan. In addition, Cryptococcus laurentii (=Papiliotrema laurentii), C. rajasthanensis (=Papiliotrema rajasthanensis), C. podzolicus (=Saitozyma podzolica) and C. flavescens (=Papiliotrema flavescens) occurred in 0.5% each. The recovery of C. flavescens and C. podzolicus was new findings for India. One more noteworthy finding was isolation of a new yeast, recently classified as Saitozyma cassiae sp. Novo. The previous strain of this yeast came from tree bark debris in South India. Our isolates came from decayed wood inside a trunk hollow of an Acacia tree in, Bharatpur Bird Sanctuary, Rajasthan. The isolations of novel strains of Cutaneotrichosporon moniliiforme from decayed wood of a Pinus tree was another significant finding. Phenotypically, they differed from T. moniliforme by being encapsulated cells, had melanin-like pigment production and were unable to assimilate d-manitol and d-melezitose. AFLP analysis showed a distinctive banding profile vis-a-vis the reference strains of T. moniliiforme and Cryptotrichosporon anacardii.
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Affiliation(s)
- Anupam Prakash
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Harbans S Randhawa
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Zia U Khan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius - Wilhelmina Hospital, Nijmegen, The Netherlands.,Department of Medical Mycology, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius - Wilhelmina Hospital, Nijmegen, The Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Utrecht, The Netherlands
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
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8
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Vanhove M, Beale MA, Rhodes J, Chanda D, Lakhi S, Kwenda G, Molloy S, Karunaharan N, Stone N, Harrison TS, Bicanic T, Fisher MC. Genomic epidemiology of Cryptococcus yeasts identifies adaptation to environmental niches underpinning infection across an African HIV/AIDS cohort. Mol Ecol 2017; 26:1991-2005. [PMID: 27862555 PMCID: PMC5412878 DOI: 10.1111/mec.13891] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 10/15/2016] [Accepted: 10/17/2016] [Indexed: 12/21/2022]
Abstract
Emerging infections caused by fungi have become a widely recognized global phenomenon and are causing an increasing burden of disease. Genomic techniques are providing new insights into the structure of fungal populations, revealing hitherto undescribed fine-scale adaptations to environments and hosts that govern their emergence as infections. Cryptococcal meningitis is a neglected tropical disease that is responsible for a large proportion of AIDS-related deaths across Africa; however, the ecological determinants that underlie a patient's risk of infection remain largely unexplored. Here, we use genome sequencing and ecological genomics to decipher the evolutionary ecology of the aetiological agents of cryptococcal meningitis, Cryptococcus neoformans and Cryptococcus gattii, across the central African country of Zambia. We show that the occurrence of these two pathogens is differentially associated with biotic (macroecological) and abiotic (physical) factors across two key African ecoregions, Central Miombo woodlands and Zambezi Mopane woodlands. We show that speciation of Cryptococcus has resulted in adaptation to occupy different ecological niches, with C. neoformans found to occupy Zambezi Mopane woodlands and C. gattii primarily recovered from Central Miombo woodlands. Genome sequencing shows that C. neoformans causes 95% of human infections in this region, of which over three-quarters belonged to the globalized lineage VNI. We show that VNI infections are largely associated with urbanized populations in Zambia. Conversely, the majority of C. neoformans isolates recovered in the environment belong to the genetically diverse African-endemic lineage VNB, and we show hitherto unmapped levels of genomic diversity within this lineage. Our results reveal the complex evolutionary ecology that underpins the reservoirs of infection for this, and likely other, deadly pathogenic fungi.
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MESH Headings
- Adaptation, Physiological/genetics
- Cryptococcus gattii/genetics
- Cryptococcus neoformans/genetics
- DNA Barcoding, Taxonomic
- DNA, Fungal/genetics
- DNA, Ribosomal Spacer/genetics
- Forests
- Genetics, Population
- Genome, Fungal
- Genomics
- Humans
- Meningitis, Cryptococcal/epidemiology
- Meningitis, Cryptococcal/microbiology
- Models, Biological
- Phylogeny
- Plant Bark/microbiology
- Polymorphism, Single Nucleotide
- Soil Microbiology
- Trees/microbiology
- Zambia
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Affiliation(s)
- Mathieu Vanhove
- Department of Infectious Disease Epidemiology, St Mary's Hospital, Imperial College London, London, W2 1PG, UK
| | - Mathew A Beale
- Department of Infectious Disease Epidemiology, St Mary's Hospital, Imperial College London, London, W2 1PG, UK
- Institute of Infection and Immunity, St. George's University of London, Blackshaw Road, London SW17 0QT, UK
- Division of Infection & Immunity, University College London, Gower St, London WC1E 6BT, UK
| | - Johanna Rhodes
- Department of Infectious Disease Epidemiology, St Mary's Hospital, Imperial College London, London, W2 1PG, UK
| | - Duncan Chanda
- School of Medicine, University of Zambia, Nationalist Road, PO Box 50110, Lusaka, Zambia
| | - Shabir Lakhi
- School of Medicine, University of Zambia, Nationalist Road, PO Box 50110, Lusaka, Zambia
| | - Geoffrey Kwenda
- Department of Biomedical Sciences, University of Zambia, PO Box 32379, Lusaka, Zambia
| | - Sile Molloy
- Institute of Infection and Immunity, St. George's University of London, Blackshaw Road, London SW17 0QT, UK
| | - Natasha Karunaharan
- Institute of Infection and Immunity, St. George's University of London, Blackshaw Road, London SW17 0QT, UK
| | - Neil Stone
- Institute of Infection and Immunity, St. George's University of London, Blackshaw Road, London SW17 0QT, UK
| | - Thomas S Harrison
- Institute of Infection and Immunity, St. George's University of London, Blackshaw Road, London SW17 0QT, UK
| | - Tihana Bicanic
- Institute of Infection and Immunity, St. George's University of London, Blackshaw Road, London SW17 0QT, UK
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology, St Mary's Hospital, Imperial College London, London, W2 1PG, UK
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9
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Normand AC, Ranque S, Cassagne C, Gaudart J, Sallah K, Charpin DA, Piarroux R. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings. ANNALS OF OCCUPATIONAL HYGIENE 2015; 60:161-75. [DOI: 10.1093/annhyg/mev075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/23/2015] [Indexed: 12/30/2022]
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10
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Phylogenetic analysis of phenotypically characterized Cryptococcus laurentii isolates reveals high frequency of cryptic species. PLoS One 2014; 9:e108633. [PMID: 25251413 PMCID: PMC4177401 DOI: 10.1371/journal.pone.0108633] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/22/2014] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Although Cryptococcus laurentii has been considered saprophytic and its taxonomy is still being described, several cases of human infections have already reported. This study aimed to evaluate molecular aspects of C. laurentii isolates from Brazil, Botswana, Canada, and the United States. METHODS In this study, 100 phenotypically identified C. laurentii isolates were evaluated by sequencing the 18S nuclear ribosomal small subunit rRNA gene (18S-SSU), D1/D2 region of 28S nuclear ribosomal large subunit rRNA gene (28S-LSU), and the internal transcribed spacer (ITS) of the ribosomal region. RESULTS BLAST searches using 550-bp, 650-bp, and 550-bp sequenced amplicons obtained from the 18S-SSU, 28S-LSU, and the ITS region led to the identification of 75 C. laurentii strains that shared 99-100% identity with C. laurentii CBS 139. A total of nine isolates shared 99% identity with both Bullera sp. VY-68 and C. laurentii RY1. One isolate shared 99% identity with Cryptococcus rajasthanensis CBS 10406, and eight isolates shared 100% identity with Cryptococcus sp. APSS 862 according to the 28S-LSU and ITS regions and designated as Cryptococcus aspenensis sp. nov. (CBS 13867). While 16 isolates shared 99% identity with Cryptococcus flavescens CBS 942 according to the 18S-SSU sequence, only six were confirmed using the 28S-LSU and ITS region sequences. The remaining 10 shared 99% identity with Cryptococcus terrestris CBS 10810, which was recently described in Brazil. Through concatenated sequence analyses, seven sequence types in C. laurentii, three in C. flavescens, one in C. terrestris, and one in the C. aspenensis sp. nov. were identified. CONCLUSIONS Sequencing permitted the characterization of 75% of the environmental C. laurentii isolates from different geographical areas and the identification of seven haplotypes of this species. Among sequenced regions, the increased variability of the ITS region in comparison to the 18S-SSU and 28S-LSU regions reinforces its applicability as a DNA barcode.
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Alvarez C, Barbosa GG, Oliveira RDVCD, Morales BP, Wanke B, Lazéra MDS. Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples. Mem Inst Oswaldo Cruz 2013; 108:126-9. [PMID: 23440129 PMCID: PMC3974326 DOI: 10.1590/s0074-02762013000100023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 08/20/2012] [Indexed: 11/22/2022] Open
Abstract
In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoculated on 10 Niger seed agar (NSA) plates. The conventional technique (CT) yielded a greater number of positive samples and indicated a higher fungal density [in colony forming units per gram of wood (CFU.g-1) ] compared to the humid swab technique (ST). However, the difference in positive and false negative results between the CT-ST was not significant. The threshold of detection for the CT was 0.05.103 CFU.g-1, while the threshold for the ST was greater than 0.1.103 CFU-1. No colonies were recovered using the dry swab technique. We also determined the viability of Cryptococcus in wood samples stored for 45 days at 25ºC using the CT and ST and found that samples not only continued to yield a positive response, but also exhibited an increase in CFU.g-1, suggesting that Cryptococcus is able to grow in stored environmental samples. The ST.1, in which samples collected with swabs were immediately plated on NSA medium, was more efficient and less laborious than either the CT or ST and required approximately 10 min to perform; however, additional studies are needed to validate this technique.
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Affiliation(s)
- Christian Alvarez
- Laboratorio de Micologia, Hospital del Niño Jesús, Tucumán, Argentina
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12
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Ferreira AS, Sampaio A, Maduro AP, Silva I, Teles F, Martins MDL, Inácio J. Genotypic diversity of environmentalCryptococcus neoformansisolates from Northern Portugal. Mycoses 2013; 57:98-104. [DOI: 10.1111/myc.12106] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 05/27/2013] [Accepted: 06/11/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Ana Sofia Ferreira
- Laboratório Nacional de Investigação Veterinária; Instituto Nacional de Investigação Agrária e Veterinária; Lisbon Portugal
- Microbiology Unit; Instituto de Higiene e Medicina Tropical; Universidade Nova de Lisboa; Lisbon Portugal
| | - Ana Sampaio
- Departamento de Biologia e Ambiente; Centro de Investigação e de Tecnologias Agroambientais e Biológicas (CITAB); Universidade de Trás-os-Montes e Alto Douro (UTAD); Vila Real Portugal
| | - Ana Paula Maduro
- Microbiology Unit; Instituto de Higiene e Medicina Tropical; Universidade Nova de Lisboa; Lisbon Portugal
| | - Inês Silva
- Microbiology Unit; Instituto de Higiene e Medicina Tropical; Universidade Nova de Lisboa; Lisbon Portugal
| | - Fernando Teles
- Microbiology Unit; Instituto de Higiene e Medicina Tropical; Universidade Nova de Lisboa; Lisbon Portugal
- Centre for Malaria and Tropical Diseases; Instituto de Higiene e Medicina Tropical; Universidade Nova de Lisboa; Lisbon Portugal
| | - Maria da Luz Martins
- Microbiology Unit; Instituto de Higiene e Medicina Tropical; Universidade Nova de Lisboa; Lisbon Portugal
- Faculdade de Ciências e Tecnologia; Departamento de Ciências da Vida; Centro de Recursos Microbiológicos; Universidade Nova de Lisboa; Lisbon Portugal
| | - João Inácio
- Laboratório Nacional de Investigação Veterinária; Instituto Nacional de Investigação Agrária e Veterinária; Lisbon Portugal
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Cogliati M. Global Molecular Epidemiology of Cryptococcus neoformans and Cryptococcus gattii: An Atlas of the Molecular Types. SCIENTIFICA 2013; 2013:675213. [PMID: 24278784 PMCID: PMC3820360 DOI: 10.1155/2013/675213] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 12/11/2012] [Indexed: 05/08/2023]
Abstract
Cryptococcosis is a fungal disease affecting more than one million people per year worldwide. The main etiological agents of cryptococcosis are the two sibling species Cryptococcus neoformans and Cryptococcus gattii that present numerous differences in geographical distribution, ecological niches, epidemiology, pathobiology, clinical presentation and molecular characters. Genotyping of the two Cryptococcus species at subspecies level supplies relevant information to understand how this fungus has spread worldwide, the nature of its population structure, and how it evolved to be a deadly pathogen. At present, nine major molecular types have been recognized: VNI, VNII, VNB, VNIII, and VNIV among C. neoformans isolates, and VGI, VGII, VGIII, and VGIV among C. gattii isolates. In this paper all the information available in the literature concerning the isolation of the two Cryptococcus species has been collected and analyzed on the basis of their geographical origin, source of isolation, level of identification, species, and molecular type. A detailed analysis of the geographical distribution of the major molecular types in each continent has been described and represented on thematic maps. This study represents a useful tool to start new epidemiological surveys on the basis of the present knowledge.
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Affiliation(s)
- Massimo Cogliati
- Lab. Micologia Medica, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Pascal 36, 20133 Milano, Italy
- *Massimo Cogliati:
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Chowdhary A, Randhawa HS, Boekhout T, Hagen F, Klaassen CH, Meis JF. Temperate climate niche for Cryptococcus gattii in Northern Europe. Emerg Infect Dis 2012; 18:172-4. [PMID: 22261398 PMCID: PMC3310122 DOI: 10.3201/eid1801.111190] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
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15
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Illnait-Zaragozí MT, Martínez-Machín GF, Fernández-Andreu CM, Perurena-Lancha MR, Theelen B, Boekhout T, Meis JF, Klaassen CH. Environmental isolation and characterisation of Cryptococcus species from living trees in Havana city, Cuba. Mycoses 2012; 55:e138-44. [DOI: 10.1111/j.1439-0507.2012.02168.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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16
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Colom MF, Hagen F, Gonzalez A, Mellado A, Morera N, Linares C, García DF, Peñataro JS, Boekhout T, Sánchez M. Ceratonia siliqua(carob) trees as natural habitat and source of infection byCryptococcus gattiiin the Mediterranean environment. Med Mycol 2012; 50:67-73. [DOI: 10.3109/13693786.2011.574239] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chowdhary A, Rhandhawa HS, Prakash A, Meis JF. Environmental prevalence of Cryptococcus neoformans and Cryptococcus gattii in India: an update. Crit Rev Microbiol 2011; 38:1-16. [PMID: 22133016 DOI: 10.3109/1040841x.2011.606426] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
An overview of work done to-date in India on environmental prevalence, population structure, seasonal variations and antifungal susceptibility of Cryptococcus neoformans and Cryptococcus gattii is presented. The primary ecologic niche of both pathogens is decayed wood in trunk hollows of a wide spectrum of host trees, representing 18 species. Overall, C. neoformans showed a higher environmental prevalence than that of C. gattii which was not found in the avian habitats. Apart from their arboreal habitat, both species were demonstrated in soil and air in close vicinity of their tree hosts. In addition, C. neoformans showed a strong association with desiccated avian excreta. An overwhelming number of C. neoformans strains belonged to genotype AFLP1/VNI, var. grubii (serotype A), whereas C. gattii strains were genotype AFLP4/VGI, serotype B. All of the environmental strains of C. neoformans and C. gattii were mating type α (MATα). Contrary to the Australian experience, Eucalyptus trees were among the epidemiologically least important and, therefore, the hypothesis of global spread of C. gattii through Australian export of infected Eucalyptus seeds is rebutted. Reference is made to long-term colonization of an abandoned, old timber beam of sal wood (Shorea robusta) by a melanin positive (Mel(+)) variant of Cryptococcus laurentii that was pathogenic to laboratory mice.
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Affiliation(s)
- Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, India
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Chowdhary A, Hiremath SS, Sun S, Kowshik T, Randhawa HS, Xu J. Genetic differentiation, recombination and clonal expansion in environmental populations of Cryptococcus gattii in India. Environ Microbiol 2011; 13:1875-88. [PMID: 21631689 DOI: 10.1111/j.1462-2920.2011.02510.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cryptococcus gattii is a ubiquitous eukaryotic pathogen capable of causing life-threatening infections in a wide variety of hosts, including both immunocompromised and immunocompetent humans. Since infections by C. gattii are predominantly obtained from environmental exposures, understanding environmental populations of this pathogen is critical, especially in countries like India with a large population and with environmental conditions conducive for the growth of C. gattii. In this study, we analysed 109 isolates of C. gattii obtained from hollows of nine tree species from eight geographic locations in India. Multilocus sequence typing was conducted for all isolates using nine gene fragments. All 109 isolates belonged to the VGI group and were mating type α. Population genetic analyses revealed limited evidence of recombination but unambiguous evidence for clonal reproduction and expansion. However, the observed clonal expansion has not obscured the significant genetic differentiation among populations from either different geographic areas or different host tree species. A positive correlation was observed between genetic distance and geographic distance. The results obtained here for environmental populations of C. gattii showed both similarities and differences with those of the closely related Cryptococcus neoformans var. grubii from similar locations and host tree species in India.
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Affiliation(s)
- Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 110 007, India
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Randhawa HS, Kowshik T, Chowdhary A, Prakash A, Khan ZU, Xu J. Seasonal variations in the prevalence ofCryptococcus neoformansvar.grubiiandCryptococcus gattiiin decayed wood inside trunk hollows of diverse tree species in north-western India: a retrospective study. Med Mycol 2011; 49:320-3. [DOI: 10.3109/13693786.2010.516457] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ferreira-Paim K, Andrade-Silva L, Mora DJ, Pedrosa AL, Rodrigues V, Silva-Vergara ML. Genotyping of Cryptococcus neoformans isolated from captive birds in Uberaba, Minas Gerais, Brazil. Mycoses 2010; 54:e294-300. [PMID: 20492533 DOI: 10.1111/j.1439-0507.2010.01901.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To evaluate Cryptococcus spp. molecular types isolated from captive birds' droppings, an epidemiological survey was carried out in Uberaba, Minas Gerais, Brazil, from December 2006 to September 2008. A total of 253 samples of bird excreta (120 fresh and 133 dry) were collected from pet shop cages and houses in different neighbourhoods. Cryptococcus neoformans was isolated in 19 (14.28%) dry samples and one fresh sample (0.84%). Cryptococcus laurentii was recovered from seven (5.26%) dry samples, but not in the fresh samples. The canavanine-glycine-bromothymol blue test was positive in all but one of the C. laurentii isolates. Cryptococcus neoformans molecular typing was performed using URA5-RFLP and the mating type locus using mating type specific PCR. Nineteen (95.0%) presented genotype VNI and one VNII (5.0%). In addition, all isolates presented mating type α. Thus, the genotype of the environmental C. neoformans isolates observed in this study is in accordance with others already reported around the world and adds information about its distribution in Brazil. Cryptococcus laurentii strains were typed using URA5-RFLP and M13 fingerprinting, which showed similar profiles among them. Thus, despite the low number of C. laurentii isolates analysed, their molecular profile is different from another already reported.
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Affiliation(s)
- Kennio Ferreira-Paim
- Disciplina de Doenças Infecciosas Parasitárias, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
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Genotypic characterization of environmental isolates of Cryptococcus gattii from Puerto Rico. Mycopathologia 2010; 170:279-85. [PMID: 20306144 DOI: 10.1007/s11046-010-9296-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
Abstract
Cryptococcus neoformans and Cryptococcus gattii are found in distinct environments with some overlap around different parts of the world. However, no systematic surveys of these two pathogens have been reported from Puerto Rico, a tropical island uniquely situated between mainland USA and countries in South America. We carried out an exhaustive environmental survey in southwestern Puerto Rico for pathogenic Cryptococcus species. Twenty-two presumptive isolates of C. gattii from cacti and tree detritus were characterized in detail by physiological and molecular methods and seventeen strains were confirmed as C. gattii. Cryptococcus gattii isolates were haploid and majority of them were MATa [corrected] strains. Sixteen out of seventeen C. gattii isolates belonged to VGII/AFLP6 genotype while one isolate was a VGIV/AFLP7 genotype. The results are significant as Puerto Rico strains are distinct from VGIII/AFLP5 strains reported from Southern California, but similar to C. gattii VGII/AFLP6 molecular type implicated in recent outbreaks of cryptococcosis in Pacific Northwest and British Columbia, Canada, but different in its M13 fingerprinting, and a common genotype in South America.
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Randhawa HS, Kowshik T, Chowdhary A, Preeti Sinha K, Khan ZU, Sun S, Xu J. The expanding host tree species spectrum of Cryptococcus gattii and Cryptococcus neoformans and their isolations from surrounding soil in India. Med Mycol 2009; 46:823-33. [PMID: 18608895 DOI: 10.1080/13693780802124026] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
This study reports the widespread prevalence of Cryptococcus neoformans and Cryptococcus gattii in decayed wood inside trunk hollows of 14 species representing 12 families of trees and from soil near the base of various host trees from Delhi and several places in the Indian states of Uttar Pradesh, Haryana, Tamil Nadu and Chandigarh Union Territory. Of the 311 trees from which samples were obtained, 64 (20.5%) were found to contain strains of the C. neoformans species complex. The number of trees positive for C. neoformans var grubii (serotypeA) was 51 (16.3%), for C. gattii (serotype B) 24 (7.7%) and for both C. neoformans and C. gattii 11 (3.5%). The overall prevalence of C. neoformans species complex in decayed wood samples was 19.9% (111/556). There was no obvious correlation between the prevalence of these two yeast species and the species of host trees. The data on prevalence of C. gattii (24%) and C. neoformans (26%) in soil around the base of some host trees indicated that soil is another important ecologic niche for these two Cryptococcus species in India. Among our sampled tree species, eight and six were recorded for the first time as hosts for C. neoformans var grubii and C. gattii, respectively. A longitudinal surveillance of 8 host tree species over 0.7 to 2.5 years indicated long term colonization of Polyalthia longifolia, Mimusops elengi and Manilkara hexandra trees by C. gattii and/or C. neoformans. The mating type was determined for 153 of the isolates, including 98 strains of serotype A and 55 of serotype B and all proved to be mating type alpha (MAT alpha). Our observations document the rapidly expanding spectrum of host tree species for C. gattii and C. neoformans and indicate that decayed woods of many tree species are potentially suitable ecological niches for both pathogens.
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Affiliation(s)
- H S Randhawa
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi-110 007, India.
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Hiremath SS, Chowdhary A, Kowshik T, Randhawa HS, Sun S, Xu J. Long-distance dispersal and recombination in environmental populations of Cryptococcus neoformans var. grubii from India. MICROBIOLOGY-SGM 2008; 154:1513-1524. [PMID: 18451060 DOI: 10.1099/mic.0.2007/015594-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The basidiomycete yeast Cryptococcus neoformans is a cause of significant morbidity and mortality in immunocompromised hosts throughout the world. The sporadic nature of the infection and the limited empirical evidence for direct human-to-human transmission have led to the belief that infections in humans are predominantly caused by the inhalation of basidiospores from environmental sources. Therefore, analysing the structure of environmental populations of C. neoformans can significantly increase our understanding of its ecology, evolution and epidemiology. Decaying wood is a rich source of organic and inorganic compounds and is known to be a suitable ecological niche for many micro-organisms, including C. neoformans. However, relatively little is known about the population structure of C. neoformans sampled from decaying wood. In this study, we analysed samples of C. neoformans var. grubii colonizing decaying wood in tree hollows of nine tree species in five geographical locations (Delhi, Bulandshahar, Hathras, Amritsar and Amrouli) in north-western India. Multilocus sequence typing was conducted using five gene fragments for each of 78 isolates. All isolates belonged to mating type alpha. Population-genetic analyses identified no evidence for significant differentiation among populations belonging to either different geographical areas or different host tree species. Interestingly, despite the lack of mating type a strains in our survey, we found unambiguous evidence for recombination in our population analyses. Our results are consistent with the hypothesis of long-distance dispersal and recombination in environmental populations of this species in India.
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Affiliation(s)
- Sanjay S Hiremath
- Center for Environmental Genomics, Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, 110 007 Delhi, India
| | - Tusharantak Kowshik
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, 110 007 Delhi, India
| | - Harbans S Randhawa
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, 110 007 Delhi, India
| | - Sheng Sun
- Center for Environmental Genomics, Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Jianping Xu
- Center for Environmental Genomics, Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
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Xue C, Tada Y, Dong X, Heitman J. The human fungal pathogen Cryptococcus can complete its sexual cycle during a pathogenic association with plants. Cell Host Microbe 2007; 1:263-73. [PMID: 18005707 DOI: 10.1016/j.chom.2007.05.005] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 04/19/2007] [Accepted: 05/21/2007] [Indexed: 12/17/2022]
Abstract
Cryptococcus is a globally distributed human fungal pathogen that primarily afflicts immunocompromised individuals. How and why this human fungal pathogen associates with plants and how this environmental niche influences its life cycle remains a mystery. We established Cryptococcus-Arabidopsis and Cryptococcus-Eucalyptus systems and discovered that Cryptococcus proliferates and mates on plant surfaces. Mating efficiency of C. gattii was markedly enhanced on plants and myo-inositol and indole acetic acid were specific plant products that stimulated mating. On Arabidopsis, dwarfing and chlorosis were observed following infection with a fungal mixture of two opposite mating-type strains, but not with either mating-type alone. This infection process is countered by the plant jasmonate-mediated defense mechanism. These findings reveal that Cryptococcus can parasitically interact with plants to complete its sexual cycle, which may impact an understanding of the origin and evolution of both plant and animal fungal pathogens in nature.
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Affiliation(s)
- Chaoyang Xue
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA
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Khan ZU, Randhawa HS, Kowshik T, Chowdhary A, Chandy R. Antifungal susceptibility of Cryptococcus neoformans and Cryptococcus gattii isolates from decayed wood of trunk hollows of Ficus religiosa and Syzygium cumini trees in north-western India. J Antimicrob Chemother 2007; 60:312-6. [PMID: 17553813 DOI: 10.1093/jac/dkm192] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND We present antifungal susceptibility data on environmental isolates of Cryptococcus neoformans (serotype A, n=117) and Cryptococcus gattii (serotype B, n=65) cultured from decayed wood of trunk hollows of Ficus religiosa and Syzygium cumini trees. METHODS Susceptibilities to amphotericin B, fluconazole, ketoconazole, itraconazole and voriconazole were determined by using Etest. The MICs were read after 48 h as per the guidelines provided by the manufacturer. RESULTS The MIC90s and susceptibility ranges for C. neoformans isolates were as follows: 0.094 (0.004-0.25) mg/L for amphotericin B, 4 (0.032-12) mg/L for fluconazole, 0.094 (0.004-0.75) mg/L for itraconazole, 0.064 (0.002-0.19) mg/L for ketoconazole, and 0.047 (0.006-0.125) mg/L for voriconazole, whereas for C. gattii isolates these were 0.125 (0.023-0.5) mg/L for amphotericin B, 8 (0.032-16) mg/L for fluconazole, 0.75 (0.006-2) mg/L for itraconazole, 0.125 (0.003-0.19) mg/L for ketoconazole, and 0.094 (0.004-0.125) mg/L for voriconazole. A comparison of the geometric means of MICs (mg/L) revealed that C. gattii was less susceptible than C. neoformans to amphotericin B (0.075 versus 0.051, P=0.0003), fluconazole (2.912 versus 2.316, P=0.003), itraconazole (0.198 versus 0.0344, P<0.0001), ketoconazole (0.072 versus 0.037, P<0.0001), and voriconazole (0.045 versus 0.023, P<0.0001). CONCLUSIONS The antifungal susceptibility data obtained in this study indicate that the occurrence of primary resistance among environmental isolates of C. neoformans serotype A and C. gattii serotype B is rare, and serotype B isolates are less susceptible than serotype A isolates.
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Affiliation(s)
- Zia U Khan
- Mycology Reference Laboratory, Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait.
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Kidd SE, Chow Y, Mak S, Bach PJ, Chen H, Hingston AO, Kronstad JW, Bartlett KH. Characterization of environmental sources of the human and animal pathogen Cryptococcus gattii in British Columbia, Canada, and the Pacific Northwest of the United States. Appl Environ Microbiol 2006; 73:1433-43. [PMID: 17194837 PMCID: PMC1828779 DOI: 10.1128/aem.01330-06] [Citation(s) in RCA: 177] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cryptococcus gattii has recently emerged as a primary pathogen of humans and wild and domesticated animals in British Columbia, particularly on Vancouver Island. C. gattii infections are typically infections of the pulmonary and/or the central nervous system, and the incidence of infection in British Columbia is currently the highest reported globally. Prior to this emergence, the environmental distribution of and the extent of colonization by C. gattii in British Columbia were unknown. We characterized the environmental sources and potential determinants of colonization in British Columbia. C. gattii was isolated from tree surfaces, soil, air, freshwater, and seawater, and no seasonal prevalence was observed. The C. gattii concentrations in air samples were significantly higher during the warm, dry summer months, although potentially infectious propagules (<3.3 microm in diameter) were present throughout the year. Positive samples were obtained from many different areas of British Columbia, and some locations were colonization "hot spots." C. gattii was generally isolated from acidic soil, and geographic differences in soil pH may influence the extent of colonization. C. gattii soil colonization also was associated with low moisture and low organic carbon contents. Most of the C. gattii isolates recovered belonged to the VGIIa genetic subtype; however, sympatric colonization by the VGIIb strain was observed at most locations. At one sampling site, VGIIa, VGIIb, VGI, and the Cryptococcus neoformans serotype AD hybrid all were coisolated. Our findings indicate extensive colonization by C. gattii within British Columbia and highlight an expansion of the ecological niche of this pathogen.
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Affiliation(s)
- Sarah E Kidd
- School of Occupational and Environmental Hygiene, 364-2206 East Mall, Vancouver, University of British Columbia V6T 1Z3, Canada
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Abstract
Cryptococcus neoformans is a major cause of fungal meningoencephalitis in immunocompromised patients. Despite recent advances in the genetics and molecular biology of C. neoformans, and improved techniques for molecular epidemiology, aspects of the ecology, population structure, and mode of reproduction of this environmental pathogen remain to be established. Application of recent insights into the life cycle of C. neoformans and its different ways of engaging in sexual reproduction under laboratory conditions has just begun to affect research on the ecology and epidemiology of this human pathogenic fungus. The melding of these disparate disciplines should yield rich dividends in our understanding of the evolution of microbial pathogens, providing insights relevant to diagnosis, treatment, and prevention.
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Affiliation(s)
- Xiaorong Lin
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Randhawa HS, Kowshik T, Preeti Sinha K, Chowdhary A, Khan ZU, Yan Z, Xu J, Kumar A. Distribution ofCryptococcus gattiiandCryptococcus neoformansin decayed trunk wood ofSyzygium cuminitrees in north-western India. Med Mycol 2006; 44:623-30. [PMID: 17071556 DOI: 10.1080/13693780600860946] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The aim of this study is to report the regional distribution of Cryptococcus. gattii and Cryptococcus. neoformans in decayed wood inside trunk hollows of Syzygium cumini trees (Java plum, Indian black berry) investigated in Amritsar (Panjab), Meerut Cantt. and Bulandshahr (Uttar Pradesh) and Delhi, in north-western India. Two hundred and seventeen wood samples collected from 74 S. cumini trees were investigated. This includes 7 known positive S. cumini trees in Delhi subjected to a mycological surveillance for perennial colonization by C. gattii and C. neoformans. Cryptococcus gattii showed the highest prevalence (89%) in S. cumini trees in Delhi, followed by 27%, 12.5% and 9% prevalence in Bulandshahr, Amritsar City and Meerut Cantt., respectively. In contrast, C. neoformans had the highest prevalence (54%) in Amritsar, followed by 44% in Delhi, 9% in Bulandshahr and 0% in Meerut Cantt. Furthermore, 44% of the S. cumini trees in Delhi, 9% in Bulandshahr and 8% in Amritsar were concomitantly colonized by both C. gattii and C. neoformans. A mycological surveillance over 4.8-5.2 years of 7 selected S. cumini trees in Delhi revealed perennial colonization by both the Cryptococcus species. In addition, air samples taken close to the decayed trunk hollows of 4 of the perennially colonized S. cumini trees contained strains of the C. neoformans species complex. Of a random sample of 48 isolates serotyped, 26 (54%) were C. neoformans, serotype A, and 22 (46%) C. gattii, serotype B. Determination of mating type alleles was done in 44 of the isolates, comprising 31 of C. neoformans, serotype A and 13 of C.gattii, serotype B. All of them proved to be mating type alpha (MATalpha). The data on high prevalence, fungal population density, perennial colonization and aerial isolations indicate that decayed wood in trunk hollows of S. cumini trees is to-date the main well documented primary environmental niche of C. gattii and C. neoformans in north-western India. Attention is drawn to the likely health hazard posed by the environmental reservoirs of C. gattii and C. neoformans occurring in tree trunk hollows in proximity to human and animal habitations.
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Affiliation(s)
- H S Randhawa
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India.
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29
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Chaturvedi S, Ren P, Narasipura SD, Chaturvedi V. Selection of Optimal Host Strain for Molecular Pathogenesis Studies on Cryptococcus gattii. Mycopathologia 2005; 160:207-15. [PMID: 16205969 DOI: 10.1007/s11046-005-0162-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Accepted: 06/29/2005] [Indexed: 10/25/2022]
Abstract
Encapsulated yeast, Cryptococcus gattii (Cg) is a primary and emerging fungal pathogen in North America. It has a predilection for invading the central nervous system of both healthy and immunocompromised humans and animals. Recently, we initiated molecular pathogenesis studies in Cg strain NIH444 (ATCC 32609). In this report, we compared the biology and pathogenic potential of NIH444 to those of WM276, an Australian environmental isolate that is being used for the whole genome-sequencing project. Our data indicated that NIH444 is comparatively more virulent in a mouse model of cryptococcosis than is WM 276. We found robust mating of NIH444, and no mating of WM276, when tested against Cg MATa strain, NIH198. WM276 but not NIH444 was defective in filamentation and sporulation (haploid fruiting). Interestingly, NIH444 has a VGII/AFLP6 genotype similar to that of the genotype of the recent outbreak strains from Vancouver Island, British Columbia, Canada. Additionally, comparisons of nucleotide sequences of various genes also showed differences between NIH444 and WM276. Based on these observations, we conclude that NIH444 should remain the strain of choice for understanding Cg pathogenesis, especially on the North American continent.
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Affiliation(s)
- Sudha Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, NY 12208-2002, USA.
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