Genome Variation in Cryptococcus gattii, an Emerging Pathogen of Immunocompetent Hosts
نویسندگان
چکیده
Cryptococcus gattii recently emerged as the causative agent of cryptococcosis in healthy individuals in western North America, despite previous characterization of the fungus as a pathogen in tropical or subtropical regions. As a foundation to study the genetics of virulence in this pathogen, we sequenced the genomes of a strain (WM276) representing the predominant global molecular type (VGI) and a clinical strain (R265) of the major genotype (VGIIa) causing disease in North America. We compared these C. gattii genomes with each other and with the genomes of representative strains of the two varieties of Cryptococcus neoformans that generally cause disease in immunocompromised people. Our comparisons included chromosome alignments, analysis of gene content and gene family evolution, and comparative genome hybridization (CGH). These studies revealed that the genomes of the two representative C. gattii strains (genotypes VGI and VGIIa) are colinear for the majority of chromosomes, with some minor rearrangements. However, multiortholog phylogenetic analysis and an evaluation of gene/sequence conservation support the existence of speciation within the C. gattii complex. More extensive chromosome rearrangements were observed upon comparison of the C. gattii and the C. neoformans genomes. Finally, CGH revealed considerable variation in clinical and environmental isolates as well as changes in chromosome copy numbers in C. gattii isolates displaying fluconazole heteroresistance.
منابع مشابه
Meningitis secondary to Cryptococcus gattii, an emerging pathogen affecting immunocompetent hosts
BACKGROUND Meningitis continues to be one of the most important infections diagnosed and treated by emergency physicians. Despite the advent of anti-infective therapy, meningitis carries a mortality rate of 20%-40%. In this study, we describe the first reported emergency medicine case of meningitis associated with Cryptococcus gattii to alert providers of this insidious, emerging global pathoge...
متن کاملCryptococcus gattii isolates from the British Columbia cryptococcosis outbreak induce less protective inflammation in a murine model of infection than Cryptococcus neoformans.
The fungal pathogen Cryptococcus neoformans causes approximately one million cases of cryptococcosis per year in people with AIDS. In contrast, the related species C. gattii is responsible for a much smaller number of cases, but these often occur in immunocompetent people. In fact, C. gattii has emerged in the last decade as the frequent cause of cryptococcosis in otherwise healthy people in Br...
متن کاملMLST 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
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 characte...
متن کاملPrimary cutaneous cryptococcal infection with subsequent erythema nodosum in a 10-year-old immunocompetent girl
EN: erythema nodosum PCC: primary cutaneous cryptococcal INTRODUCTION Members of the Cryptococcus genus are opportunistic encapsulated yeasts that cause significant morbidity and mortality most often in immunocompromised hosts. Clinically, cryptococcal infections manifestmost commonlyasmeningitis or a respiratory infection. The cryptococcal species are Cryptococcus neoformans, Cryptococcus gatt...
متن کامل‘Division of labour’ in response to host oxidative burst drives a fatal Cryptococcus gattii outbreak
Cryptococcus gattii is an emerging intracellular pathogen and the cause of the largest primary outbreak of a life-threatening fungal disease in a healthy population. Outbreak strains share a unique mitochondrial gene expression profile and an increased ability to tubularize their mitochondria within host macrophages. However, the underlying mechanism that causes this lineage of C. gattii to be ...
متن کامل