Chromosome copy number variation in Cryptococcus neoformans influences virulence and occurs in isolates from AIDS patients
Ontology highlight
ABSTRACT:
ORGANISM(S): Cryptococcus neoformans Cryptococcus neoformans var. grubii H99
PROVIDER: GSE29675 | GEO | 2011/06/01
SECONDARY ACCESSION(S): PRJNA141193
REPOSITORIES: GEO
Similar Datasets
Project description:Influence of copy number changes at several chromosomes to melanin production and virulence of Cryptococcus neoformans
2011-04-19 | GSE28673 | GEO
Project description:The adaptation of pathogenic fungi to the host environment via large-scale genomic changes is a poorly characterized phenomenon. Cryptococcus neoformans is the leading cause of fungal meningoencephalitis in HIV/AIDS patients, and we recently discovered clinical strains of the fungus that are disomic for chromosome 13. Here, we examined the genome plasticity and phenotypes of monosomic and disomic strains, and compared their virulence in a mouse model of cryptococcosisIn an initial set of strains, melanin production was correlated with monosomy at chromosome 13, and disomic variants were less melanized and attenuated for virulence in mice. After growth in culture or passage through mice, subsequent strains were identified that varied in melanin formation and exhibited copy number changes for other chromosomes. The correlation between melanin and disomy at chromosome 13 was observed for some but not all strains. A survey of environmental and clinical isolates maintained in culture revealed few occurrences of disomic chromosomes. However, an examination of isolates that were freshly collected from the cerebrospinal fluid of AIDS patients and minimally cultured provided evidence for infections with multiple strains and copy number variation.Overall, these results suggest that the genome of C. neoformans exhibits a greater degree of plasticity than previously appreciated. Furthermore, the expression of an essential virulence factor and the severity of disease are associated with genome variation. The occurrence of chromosomal variation in isolates from AIDS patients, combined with the observed influence of disomy on virulence, indicates that genome plasticity may have clinical relevance.
| S-EPMC3221739 | biostudies-literature
Project description:This SuperSeries is composed of the following subset Series: GSE29627: Chromosome copy number variation in Cryptococcus neoformans influences virulence and occurs in isolates from AIDS patients: CBS7779 black and white strains GSE29671: Chromosome copy number variation in Cryptococcus neoformans influences virulence and occurs in isolates from AIDS patients: clinal and environmental strains Refer to individual Series
2011-05-31 | E-GEOD-29675 | biostudies-arrayexpress
Project description:Influence of copy number changes at several chromosomes to melanin production and virulence of Cryptococcus neoformans Black(B4) and white(W2) strains were compared to each other. Black variant from white strain (W2BA1) is also compared to the black strain(B4).
2011-04-19 | E-GEOD-28673 | biostudies-arrayexpress
Project description:The adaptation of fungal pathogens to the host environment via large-scale genomic changes is a poorly characterized phenomenon. We recently discovered clinical strains of Cryptococcus neoformans, the leading cause of fungal meningoencephalitis in HIV/AIDS patients, which are disomic for chromosome 13. In the current study, we examined the relationship between disomy, expression of the virulence factor melanin and virulence in a mouse model of cryptococcosis. We found that melanin production was correlated with monosomy at chromosome 13, and that disomic variants were less melanized and attenuated for virulence in mice. Changes in the copy number of other chromosomes were also detected in strains showing variation in melanin formation after growth in culture and after passage through mice. A survey of environmental and clinical isolates maintained in culture revealed few occurrences of disomic chromosomes. However, an examination of isolates that were freshly collected from the cerebral spinal fluid of AIDS patients and minimally cultured provided evidence for mixed infections and copy number variation. Overall, these results suggest that the genome of C. neoformans exhibits a greater degree of plasticity than previously appreciated. Importantly, genome variation is associated with virulence factor expression and disease severity, and its occurrence in isolates from AIDS patients suggests that it may have clinical relevance.
2011-06-01 | GSE29671 | GEO
Project description:The adaptation of fungal pathogens to the host environment via large-scale genomic changes is a poorly characterized phenomenon. We recently discovered clinical strains of Cryptococcus neoformans, the leading cause of fungal meningoencephalitis in HIV/AIDS patients, which are disomic for chromosome 13. In the current study, we examined the relationship between disomy, expression of the virulence factor melanin and virulence in a mouse model of cryptococcosis. We found that melanin production was correlated with monosomy at chromosome 13, and that disomic variants were less melanized and attenuated for virulence in mice. Changes in the copy number of other chromosomes were also detected in strains showing variation in melanin formation after growth in culture and after passage through mice. A survey of environmental and clinical isolates maintained in culture revealed few occurrences of disomic chromosomes. However, an examination of isolates that were freshly collected from the cerebral spinal fluid of AIDS patients and minimally cultured provided evidence for mixed infections and copy number variation. Overall, these results suggest that the genome of C. neoformans exhibits a greater degree of plasticity than previously appreciated. Importantly, genome variation is associated with virulence factor expression and disease severity, and its occurrence in isolates from AIDS patients suggests that it may have clinical relevance.
2011-05-31 | GSE29627 | GEO
Project description:The adaptation of fungal pathogens to the host environment via large-scale genomic changes is a poorly characterized phenomenon. We recently discovered clinical strains of Cryptococcus neoformans, the leading cause of fungal meningoencephalitis in HIV/AIDS patients, which are disomic for chromosome 13. In the current study, we examined the relationship between disomy, expression of the virulence factor melanin and virulence in a mouse model of cryptococcosis. We found that melanin production was correlated with monosomy at chromosome 13, and that disomic variants were less melanized and attenuated for virulence in mice. Changes in the copy number of other chromosomes were also detected in strains showing variation in melanin formation after growth in culture and after passage through mice. A survey of environmental and clinical isolates maintained in culture revealed few occurrences of disomic chromosomes. However, an examination of isolates that were freshly collected from the cerebral spinal fluid of AIDS patients and minimally cultured provided evidence for mixed infections and copy number variation. Overall, these results suggest that the genome of C. neoformans exhibits a greater degree of plasticity than previously appreciated. Importantly, genome variation is associated with virulence factor expression and disease severity, and its occurrence in isolates from AIDS patients suggests that it may have clinical relevance. Genome comparison of clinal and environmental strains vs standard strain H99
2011-05-31 | E-GEOD-29671 | biostudies-arrayexpress
Project description:The adaptation of fungal pathogens to the host environment via large-scale genomic changes is a poorly characterized phenomenon. We recently discovered clinical strains of Cryptococcus neoformans, the leading cause of fungal meningoencephalitis in HIV/AIDS patients, which are disomic for chromosome 13. In the current study, we examined the relationship between disomy, expression of the virulence factor melanin and virulence in a mouse model of cryptococcosis. We found that melanin production was correlated with monosomy at chromosome 13, and that disomic variants were less melanized and attenuated for virulence in mice. Changes in the copy number of other chromosomes were also detected in strains showing variation in melanin formation after growth in culture and after passage through mice. A survey of environmental and clinical isolates maintained in culture revealed few occurrences of disomic chromosomes. However, an examination of isolates that were freshly collected from the cerebral spinal fluid of AIDS patients and minimally cultured provided evidence for mixed infections and copy number variation. Overall, these results suggest that the genome of C. neoformans exhibits a greater degree of plasticity than previously appreciated. Importantly, genome variation is associated with virulence factor expression and disease severity, and its occurrence in isolates from AIDS patients suggests that it may have clinical relevance. Genome comparison of CBS7779 black and white strains vs standard strain H99
2011-05-30 | E-GEOD-29627 | biostudies-arrayexpress
Project description:We describe a case of Cryptococcal choroiditis in a person with advanced HIV/AIDS. A 29-year-old male with AIDS presented with fever, photophobia, and ataxia secondary to cryptococcal and toxoplasma meningoencephalitis. Dilated fundoscopic examination revealed bilateral and multifocal posterior infiltrates consistent with cryptococcal choroiditis. Treatment with parenteral and intravitreal liposomal amphotericin B, oral flucytosine, and oral trimethoprim-sulfamethoxazole led to resolution of his symptoms and improvement in his vision. Our case documents a rare, intraocular opportunistic infection and highlights the importance of ophthalmologic examination in immunocompromised hosts with visual symptoms and invasive fungal infection. We discuss diagnostic and treatment considerations in cryptococcal choroiditis.
| S-EPMC7452429 | biostudies-literature
Project description:Genome variability can have a profound influence on the virulence of pathogenic microbes. The availability of genome sequences for two strains of the AIDS-associated fungal pathogen Cryptococcus neoformans presented an opportunity to use comparative genome hybridization (CGH) to examine genome variability between strains of different mating type, molecular subtype, and ploidy.Initially, CGH was used to compare the approximately 100 kilobase MATa and MATalpha mating-type regions in serotype A and D strains to establish the relationship between the Log2 ratios of hybridization signals and sequence identity. Subsequently, we compared the genomes of the environmental isolate NIH433 (MATa) and the clinical isolate NIH12 (MATalpha) with a tiling array of the genome of the laboratory strain JEC21 derived from these strains. In this case, CGH identified putative recombination sites and the origins of specific segments of the JEC21 genome. Similarly, CGH analysis revealed marked variability in the genomes of strains representing the VNI, VNII, and VNB molecular subtypes of the A serotype, including disomy for chromosome 13 in two strains. Additionally, CGH identified differences in chromosome content between three strains with the hybrid AD serotype and revealed that chromosome 1 from the serotype A genome is preferentially retained in all three strains.The genomes of serotypes A, D, and AD strains exhibit extensive variation that spans the range from small differences (such as regions of divergence, deletion, or amplification) to the unexpected disomy for chromosome 13 in haploid strains and preferential retention of specific chromosomes in naturally occurring diploids.
| S-EPMC2374700 | biostudies-literature