scholarly journals The mycobiome of Australian tree hollows in relation to the Cryptococcus gattii and C. neoformans species complexes

2019 ◽  
Vol 9 (17) ◽  
pp. 9684-9700 ◽  
Author(s):  
Laura J. Schmertmann ◽  
Laszlo Irinyi ◽  
Richard Malik ◽  
Jeff R. Powell ◽  
Wieland Meyer ◽  
...  
Keyword(s):  
Cryptococcus Gattii ◽  
Tree Hollows ◽  
Species Complexes

Flucytosine resistance in Cryptococcus gattii is indirectly mediated by the FCY2-FCY1-FUR1 pathway

2018 ◽  
Vol 56 (7) ◽  
pp. 857-867 ◽  
Author(s):  
Kiem Vu ◽  
George R Thompson ◽  
Chandler C Roe ◽  
Jane E Sykes ◽  
Elizabeth M Dreibe ◽  
...  
Keyword(s):  
Point Mutation ◽  
Molecular Mechanisms ◽  
Cytosine Deaminase ◽  
Protein S ◽  
Comparative Sequence Analysis ◽  
Cryptococcus Gattii ◽  
Clinical Isolates ◽  
Sequencing Analysis ◽  
Genomic Changes ◽  
Species Complexes

Abstract Cryptococcosis is an opportunistic fungal infection caused by members of the two sibling species complexes: Cryptococcus neoformans and Cryptococcus gattii. Flucytosine (5FC) is one of the most widely used antifungals against Cryptococcus spp., yet very few studies have looked at the molecular mechanisms responsible for 5FC resistance in this pathogen. In this study, we examined 11 C. gattii clinical isolates of the major molecular type VGIII based on differential 5FC susceptibility and asked whether there were genomic changes in the key genes involved in flucytosine metabolism. Susceptibility assays and sequencing analysis revealed an association between a point mutation in the cytosine deaminase gene (FCY1) and 5FC resistance in two of the studied 5FC resistant C. gattii VGIII clinical isolates, B9322 and JS5. This mutation results in the replacement of arginine for histidine at position 29 and occurs within a variable stretch of amino acids. Heterologous expression of FCY1 and spot sensitivity assays, however, demonstrated that this point mutation did not have any effect on FCY1 activities and was not responsible for 5FC resistance. Comparative sequence analysis further showed that no changes in the amino acid sequence and no genomic alterations were observed within 1 kb of the upstream and downstream sequences of either cytosine permeases (FCY2-4) or uracil phosphoribosyltransferase (FUR1) genes in 5FC resistant and 5FC susceptible C. gattii VGIII isolates. The herein obtained results suggest that the observed 5FC resistance in the isolates B9322 and JS5 is due to changes in unknown protein(s) or pathway(s) that regulate flucytosine metabolism.

scholarly journals Cryptococcus neoformans and Cryptococcus gattii Species Complexes in Latin America: A Map of Molecular Types, Genotypic Diversity, and Antifungal Susceptibility as Reported by the Latin American Cryptococcal Study Group

2021 ◽  
Vol 7 (4) ◽  
pp. 282
Author(s):  
Carolina Firacative ◽  
Wieland Meyer ◽  
Elizabeth Castañeda
Keyword(s):  
Latin America ◽  
Cryptococcus Neoformans ◽  
Latin American ◽  
Antifungal Susceptibility ◽  
Genotypic Diversity ◽  
Cryptococcus Gattii ◽  
Study Group ◽  
Molecular Type ◽  
Infected People ◽  
Species Complexes

Cryptococcosis, a potentially fatal mycosis, is caused by members of the Cryptococcus neoformans and Cryptococcus gattii species complexes. In Latin America, cryptococcal meningitis is still an important health threat with a significant clinical burden. Analysis of publicly available molecular data from 5686 clinical, environmental, and veterinary cryptococcal isolates from member countries of the Latin American Cryptococcal Study Group showed that, as worldwide, C. neoformans molecular type VNI is the most common cause of cryptococcosis (76.01%) in HIV-infected people, followed by C. gattii molecular type VGII (12.37%), affecting mostly otherwise healthy hosts. These two molecular types also predominate in the environment (68.60% for VNI and 20.70% for VGII). Among the scarce number of veterinary cases, VGII is the predominant molecular type (73.68%). Multilocus sequence typing analysis showed that, in Latin America, the C. neoformans population is less diverse than the C. gattii population (D of 0.7104 vs. 0.9755). Analysis of antifungal susceptibility data showed the presence of non-wild-type VNI, VGI, VGII, and VGIII isolates in the region. Overall, the data presented herein summarize the progress that has been made towards the molecular epidemiology of cryptococcal isolates in Latin America, contributing to the characterization of the genetic diversity and antifungal susceptibility of these globally spreading pathogenic yeasts.

scholarly journals Frequency and geographical distribution of genotypes and mating types of Cryptococcus neoformans and Cryptococcus gattii species complexes in Argentina

2020 ◽  
Vol 52 (3) ◽  
pp. 183-188
Author(s):  
Constanza Giselle Taverna ◽  
María Eugenia Bosco-Borgeat ◽  
Mariana Mazza ◽  
Matías Ezequiel Vivot ◽  
Graciela Davel ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Geographical Distribution ◽  
Cryptococcus Gattii ◽  
Mating Types ◽  
Species Complexes

scholarly journals Genotypes and population genetics of cryptococcus neoformans and cryptococcus gattii species complexes in Europe and the mediterranean area

2019 ◽  
Vol 129 ◽  
pp. 16-29 ◽  
Author(s):  
Massimo Cogliati ◽  
Marie Desnos-Ollivier ◽  
Ilka McCormick-Smith ◽  
Volker Rickerts ◽  
Kennio Ferreira-Paim ◽  
...  
Keyword(s):  
Population Genetics ◽  
Cryptococcus Neoformans ◽  
Mediterranean Area ◽  
Cryptococcus Gattii ◽  
Species Complexes ◽  
The Mediterranean

scholarly journals Continental Drift and Speciation of the Cryptococcus neoformans and Cryptococcus gattii Species Complexes

mSphere ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Arturo Casadevall ◽  
Joudeh B. Freij ◽  
Christopher Hann-Soden ◽  
John Taylor
Keyword(s):  
South America ◽  
Cryptococcus Neoformans ◽  
Species Complex ◽  
Continental Drift ◽  
Pathogenic Fungi ◽  
Cryptococcus Gattii ◽  
Evolutionary Divergence ◽  
Temporal Separation ◽  
Content Type ◽  
Species Complexes

ABSTRACT Genomic analysis has placed the origins of two human-pathogenic fungi, the Cryptococcus gattii species complex and the Cryptococcus neoformans species complex, in South America and Africa, respectively. Molecular clock calculations suggest that the two species separated ~80 to 100 million years ago. This time closely approximates the breakup of the supercontinent Pangea, which gave rise to South America and Africa. On the basis of the geographic distribution of these two species complexes and the coincidence of the evolutionary divergence and Pangea breakup times, we propose that a spatial separation caused by continental drift resulted in the emergence of the C. gattii and C. neoformans species complexes from a Pangean ancestor. We note that, despite the spatial and temporal separation that occurred approximately 100 million years ago, these two species complexes are morphologically similar, share virulence factors, and cause very similar diseases. Continuation of these phenotypic characteristics despite ancient separation suggests the maintenance of similar selection pressures throughout geologic ages.

scholarly journals Recent Advances in Cryptococcus and Cryptococcosis

2021 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Carolina Firacative ◽  
Luciana Trilles ◽  
Wieland Meyer
Keyword(s):  
Risk Factors ◽  
Fungal Infection ◽  
Cryptococcus Neoformans ◽  
Cryptococcus Gattii ◽  
Recent Advances ◽  
Species Complexes ◽  
Life Threatening ◽  
Etiological Agents

The members of the Cryptococcus neoformans and Cryptococcus gattii species complexes are the main etiological agents of cryptococcosis, a life-threatening fungal infection affecting mostly immunocompromised people, but also immunocompetent hosts or those with unrecognized risk factors [...]

scholarly journals Importance of Resolving Fungal Nomenclature: the Case of Multiple Pathogenic Species in the Cryptococcus Genus

mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Ferry Hagen ◽  
H. Thorsten Lumbsch ◽  
Valentina Arsic Arsenijevic ◽  
Hamid Badali ◽  
Sebastien Bertout ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Species Complex ◽  
Molecular Genetic ◽  
Taxonomic Revision ◽  
Fungal Disease ◽  
Cryptococcus Gattii ◽  
Species Level ◽  
Content Type ◽  
Species Complexes ◽  
Clinical Advances

ABSTRACT Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. The two varieties within C. neoformans were raised to species level, and the same was done for five genotypes within C. gattii. In a recent perspective (K. J. Kwon-Chung et al., mSphere 2:e00357-16, 2017, https://doi.org/10.1128/mSphere.00357-16 ), it was argued that this taxonomic proposal was premature and without consensus in the community. Although the authors of the perspective recognized the existence of genetic diversity, they preferred the use of the informal nomenclature “C. neoformans species complex” and “C. gattii species complex.” Here we highlight the advantage of recognizing these seven species, as ignoring these species will impede deciphering further biologically and clinically relevant differences between them, which may in turn delay future clinical advances.

Sign in / Sign up

Export Citation Format

Share Document