Project description:This experiment set contains the raw data for 8 arrays that were used in the genomic typing of the pre- and post-mouse H. pylori strains SS1 and SS2000. 10700 is the pre-mouse clinical isolate of SS1 and PMSS2000 is the pre-mouse clinical isolate of SS2000. gDNA from these strains were labeled and hybridized to H. pylori microarrays as described in Salama et al. {Salama et al. 2000 PNAS 97:14668-73}. In each case the test gDNA sample was labeled with Cy5 (red) and this was hybridized with Cy3 (green) labeled reference DNA of equal amount. The reference DNA consisted of equal amounts of gDNA from the two H. pylori strains used to make the H. pylori microarray, 26695 and J99. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
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. Keywords: other
Project description:This experiment set contains the raw data for 8 arrays that were used in the genomic typing of the pre- and post-mouse H. pylori strains SS1 and SS2000. 10700 is the pre-mouse clinical isolate of SS1 and PMSS2000 is the pre-mouse clinical isolate of SS2000. gDNA from these strains were labeled and hybridized to H. pylori microarrays as described in Salama et al. {Salama et al. 2000 PNAS 97:14668-73}. In each case the test gDNA sample was labeled with Cy5 (red) and this was hybridized with Cy3 (green) labeled reference DNA of equal amount. The reference DNA consisted of equal amounts of gDNA from the two H. pylori strains used to make the H. pylori microarray, 26695 and J99. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
Project description:To distinguish between Helicobacter pylori isolates that may cause greater disease in patients, we used whole genome expression profiling as a platform to study host-pathogen interactions and identify gene signatures associated with isolates from patients with higher cancer risk. Expression profiles were studied for 3 clinical isolates from a region of high gastric cancer incidence (PZ5056, PZ5080, PZ5086) in Colombia and 3 isolates from a region with low gastric cancer incidence in Colombia (PZ5004, PZ5024, PZ5026). Each experiment was done in triplicate by infecting monolayers of gastric epithelial cells for 1 hour with the isolates.