Article
Microbiology
Norida Velez, Nelson Vega-Vela, Marina Munoz, Paola Gomez, Patricia Escandon, Juan David Ramirez, Oscar Zaragoza, Lucia Monteoliva Diaz, Claudia-Marcela Parra-Giraldo
Summary: In this study, the relationship between phenotypes and genotypes of clinical isolates of Cryptococcus neoformans from different cities in Colombia was investigated. The study found that isolates showed variations in pigmentation, capsule size, and pathogenicity. Polymorphism analysis revealed genetic variants associated with capsule size change, melanin production, or pathogenicity. However, no clear patterns were found in the analysis of phenotype and genotype for Cryptococcus.
Article
Microbiology
Norida Velez, Lucia Monteoliva, Zilpa-Adriana Sanchez-Quitian, Ahinara Amador-Garcia, Rocio Garcia-Rodas, Andres Ceballos-Garzon, Concha Gil, Patricia Escandon, Oscar Zaragoza, Claudia-Marcela Parra-Giraldo
Summary: This study found that the combination of iron and copper can enhance the pathogenicity of Cryptococcus neoformans and increase the abundance of proteins related to virulence factors. This suggests that the uptake of metals may affect the pathogenicity of fungi.
Article
Infectious Diseases
Silvia Katherine Carvajal, Yerly Vargas-Casanova, Hector Manuel Pineda-Castaneda, Javier Eduardo Garcia-Castaneda, Zuly Jenny Rivera-Monroy, Claudia Marcela Parra-Giraldo
Summary: This study evaluated the binding and antifungal activity of chimeras composed of bovine lactoferricin (LfcinB) and buforin II (BFII) against Cryptococcus neoformans var. grubii. The chimeras showed high activity against the strains, with a synergistic effect when combined with fluconazole treatment.
Article
Infectious Diseases
Donjeta Pllana-Hajdari, Ekene P. Chidebelu, Massimo Cogliati
Summary: A total of 300 tree-associated samples were collected from green areas in three towns in Kosovo, and cultured to isolate Cryptococcus species. One soil sample from Prizren tested positive, yielding three isolates identified as C. neoformans var. neoformans (C. deneoformans), molecular type VNIV, two MAT & alpha;, and one MATa. The study reports the presence of C. neoformans strains in the environment in Kosovo and highlights the importance of monitoring pathogen distribution and the potential impacts of climate change.
Article
Microbiology
Zena M. Birkenfeld, Nikita Dittel, Thomas Harrer, Christoph Stephan, Albrecht F. Kiderlen, Volker Rickerts
Summary: The clinical isolates of Cryptococcus neoformans var. neoformans exhibit substantial phenotypic variability, with isolates from disseminated infections showing stronger melanization and larger capsules. These isolates also demonstrate increased cytotoxicity for amoeba in coincubation, indicating a potential difference in virulence potential among strains from localized and disseminated infections.
Article
Infectious Diseases
Jeng-How Yang, Po-Yen Huang, Chun-Wen Cheng, Shian-Sen Shie, Zhong-Fu Lin, Lan-Yan Yang, Chia-Hui Lee, Ting-Shu Wu
Summary: Despite treatment with antifungal drugs, mortality rates due to Cryptococcus neoformans var. grubii fungemia remain significant. Antifungal susceptibility testing does not predict clinical outcomes, with greater disease severity, high comorbidities, poor consciousness level, and inappropriate treatment associated with increased mortality in cryptococcemia cases.
Review
Immunology
Herdson Renney de Sousa, Stefania de Frazao, Getulio Pereira de Oliveira Junior, Patricia Albuquerque, Andre Moraes Nicola
Summary: Cryptococcosis, caused by Cryptococcus spp, has a high mortality rate and lacks effective prevention and treatment methods. Understanding fungal virulence and host responses could lead to improved therapies. Studies using clinical isolates to correlate laboratory and patient data have provided valuable insights into the pathophysiology of cryptococcosis.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2021)
Article
Microbiology
Daniel Paiva Agustinho, Holly Leanne Brown, Guohua Chen, Elizabeth Anne Gaylord, Jennifer Geddes-McAlister, Michael Richard Brent, Tamara Lea Doering
Summary: This study used genetic methods to identify sequence variants that influence fungal virulence. The researchers found a region containing important variants and confirmed the significant impact of a specific variant on virulence.
CELL HOST & MICROBE
(2023)
Review
Microbiology
Briggith-Nathalia Serna-Espinosa, Diomedes Guzman-Sanabria, Maribel Forero-Castro, Patricia Escandon, Zilpa Adriana Sanchez-Quitian
Summary: The Cryptococcus genus consists of over 80 species, with C. neoformans and C. gattii being pathogenic to humans. They differ in geographic distribution and environmental niche, with C. neoformans found worldwide in bird droppings and C. gattii in tropical regions associated with Eucalyptus trees. In Colombia, environmental isolates of both species complexes are mainly recovered from pigeons' excrement and Eucalyptus trees, respectively, with higher positivity in high humidity and less sunny, cold or temperate regions.
Article
Microbiology
Chen-Hsin Yu, Poppy Sephton-Clark, Jennifer L. Tenor, Dena L. Toffaletti, Charles Giamberardino, Miriam Haverkamp, Christina A. Cuomo, John R. Perfect
Summary: This study provides insights into the gene expression patterns of Cryptococcus neoformans in human cerebrospinal fluid, highlighting the importance of carbon metabolism, fatty acid synthesis, transport, cell wall structure, and stress-related gene functions during growth in this environment. Highly expressed yeast genes in human CSF include those associated with survival or virulence, as well as genes encoding hypothetical proteins. The findings contribute to understanding how the yeast responds to stress in the central nervous system, with potential implications for developing new therapeutics targeting these genes and pathways.
Article
Infectious Diseases
Izabela de Mesquita Barcia Moreira, Ana Claudia Alves Cortez, Erica Simplicio de Souza, Silviane Bezerra Pinheiro, Juliana Gomes de Souza Oliveira, Aya Sadahiro, Katia Santana Cruz, Ani Beatriz Jackisch Matsuura, Marcia de Souza Carvalho Melhem, Hagen Frickmann, Joao Vicente Braga de Souza
Summary: The study investigated the level of heteroresistance to fluconazole in clinical and environmental Cryptococcus neoformans/Cryptococcus gattii isolates from Amazonas State, Brazil. The findings showed that clinical C. gattii isolates had higher MIC values compared to environmental C. gattii and C. neoformans isolates. All isolates exhibited heteroresistance to fluconazole, with a significant proportion showing high levels of heteroresistance and the ability to adapt to even higher fluconazole concentrations. Further research is needed to understand how these levels of heteroresistance affect cryptococcosis-related outcomes.
Review
Microbiology
Katrina M. Jackson, Minna Ding, Kirsten Nielsen
Summary: The human pathogenic fungus Cryptococcus neoformans is a global health concern. Previous research has primarily focused on using reference strains to study the fungus, but studying clinical isolates has expanded our knowledge of its pathogenesis and the host-pathogen interaction during infection.
Article
Microbiology
Luz Helena Patino, Marina Munoz, Angie Lorena Ramirez, Norida Velez, Patricia Escandon, Claudia-Marcela Parra-Giraldo, Juan David Ramirez
Summary: By sequencing and analyzing the genomic architecture of 29 Colombian C. neoformans isolates, it was found that the majority belonged to the VNI molecular type. The study also revealed some SNP differences among these strains, but a low number of gene copy number variations and no changes in karyotype. These findings suggest that Colombian C. neoformans isolates may not require significant structural changes for host adaptation.
Article
Infectious Diseases
Min Chen, Yan Wang, Yingfang Li, Nan Hong, Xinlin Zhu, Weihua Pan, Wanqing Liao, Jianping Xu, Jingxia Du, Jianghan Chen
Summary: This study collected 61 environmental isolates of Cryptococcus neoformans from pigeon droppings in East China and found a high genetic diversity and azole-resistance among the isolates. The results expand the understanding of ecological niches, population genetic diversity, and azole-resistance characteristics of the yeast in East China. The research lays the foundation for further comparative analysis of the potential mechanisms for the observed differences between environmental and clinical populations of C. neoformans in China.
Article
Genetics & Heredity
Corinne Maufrais, Luciana de Oliveira, Rafael W. Bastos, Frederique Moyrand, Flavia C. G. Reis, Clara Valero, Bianca Gimenez, Luisa J. Josefowicz, Gustavo H. Goldman, Marcio L. Rodrigues, Guilhem Janbon
Summary: Genomic sequences of 53 Brazilian Cryptococcus isolates were analyzed to uncover the population structure of C. neoformans in the country, revealing an African-like structure and suggesting repeated intercontinental transports from Africa to South America. A mutator phenotype was identified in one VNBII Brazilian isolate, demonstrating how fast-evolving isolates can influence the population structure of Cryptococcus. Phenotypic analyses showed wide diversity in the expression of classical virulence traits within the set of isolates, without lineage specificity.
G3-GENES GENOMES GENETICS
(2021)