Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1195821 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The genomic diversity of 38 Bartonella henselae isolates was studied by comparative genomic hybridizations. In addition, the effect of growth time (5 or 10 days) was studied for 5 strains.
2006-08-29 | E-TABM-88 | biostudies-arrayexpress
Project description:Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, are known to exhibit diverse phenotypic traits, suggesting significant intraspecies genetic heterogeneity. Using whole-genome Bp microarrays, we experimentally mapped patterns of large-scale genomic variation in 93 South East Asian clinical, environmental, and animal Bp isolates. 14% of the reference Bp K96243 genome was variably present across the strain panel, more than double previous estimates, and both hypothetical proteins and paralogous gene pairs (PGPs) were significantly over-represented in the set of strain-variable genes. Examining patterns of PGP retention and loss, we successfully sub-categorized the PGPs into non-redundant, functionally biased, and completely redundant classes. We then identified 20 novel regions (âislandsâ) variably present between strains previously missed by computational analysis. Three of these novel islands contained lipopolysaccharide (LPS) biosynthesis genes, and strains lacking one such LPS island demonstrated reduced virulence in mouse infection assays. Clinical isolates associated with human melioidosis were strongly associated with the presence of specific genomic islands, but a common set of virulence-related genes was present in all strains. Our results suggest that most Bp strains possess a core virulence machinery capable of causing disease, but accessory functions provided by mobile elements may predispose distinct host species and ecological niches to specific individual strains. This hierarchical model of Bp virulence reconciles previous conflicting studies comparing Bp environmental and clinical isolates, and suggests novel molecular strategies for disease surveillance and outbreak detection efforts in melioidosis. Keywords: aCGH of 93 Bp strains genomic DNA of 93 Bp strains were assessed on Bp_array_v2
2008-12-25 | E-GEOD-9491 | biostudies-arrayexpress
Project description:Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, are known to exhibit diverse phenotypic traits, suggesting significant intraspecies genetic heterogeneity. Using whole-genome Bp microarrays, we experimentally mapped patterns of large-scale genomic variation in 93 South East Asian clinical, environmental, and animal Bp isolates. 14% of the reference Bp K96243 genome was variably present across the strain panel, more than double previous estimates, and both hypothetical proteins and paralogous gene pairs (PGPs) were significantly over-represented in the set of strain-variable genes. Examining patterns of PGP retention and loss, we successfully sub-categorized the PGPs into non-redundant, functionally biased, and completely redundant classes. We then identified 20 novel regions (“islands”) variably present between strains previously missed by computational analysis. Three of these novel islands contained lipopolysaccharide (LPS) biosynthesis genes, and strains lacking one such LPS island demonstrated reduced virulence in mouse infection assays. Clinical isolates associated with human melioidosis were strongly associated with the presence of specific genomic islands, but a common set of virulence-related genes was present in all strains. Our results suggest that most Bp strains possess a core virulence machinery capable of causing disease, but accessory functions provided by mobile elements may predispose distinct host species and ecological niches to specific individual strains. This hierarchical model of Bp virulence reconciles previous conflicting studies comparing Bp environmental and clinical isolates, and suggests novel molecular strategies for disease surveillance and outbreak detection efforts in melioidosis. Keywords: aCGH of 93 Bp strains
2008-12-26 | GSE9491 | GEO
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island.
2001-07-25 | E-GEOD-6 | biostudies-arrayexpress