Project description:Genomic DNA from pools of H. pylori strain G27 Clones as indicated (pools of 300 (300p) or insertions in specific mapped genes) were amplifed using the MATT method to label DNA adjacent to the site of transposon insertion with the primer pairs indicated. The left side of the transposon was labeled in the Cy3 channel (Primer S) and the right side of the transposon was labeled in the Cy5 channel (Primer N). The results of these experiments are published in Salama et al. 2004. J Bact. 186(23):7926-7935.
Project description:Genomic DNA from pools of H. pylori strain G27 Clones as indicated (pools of 300 (300p) or insertions in specific mapped genes) were amplifed using the MATT method to label DNA adjacent to the site of transposon insertion with the primer pairs indicated. The left side of the transposon was labeled in the Cy3 channel (Primer S) and the right side of the transposon was labeled in the Cy5 channel (Primer N). Keywords: reference_design
Project description:Genomic DNA from pools of H. pylori strain G27 Clones as indicated (pools of 300 (300p) or insertions in specific mapped genes) were amplifed using the MATT method to label DNA adjacent to the site of transposon insertion with the primer pairs indicated. The left side of the transposon was labeled in the Cy3 channel (Primer S) and the right side of the transposon was labeled in the Cy5 channel (Primer N). Computed
Project description:Microarray Tracking of transposon mutants for a H. pylori mouse colonization screen described in Baldwin DN et al. 2007, I&I, 75(2):??, doi:10.1128/IAI.01176-06. Screen in NSH57 H. pylori strain background. Original 50,000 clone transposon library was plated and patched to make 25 pools of 48 clones. Clones were infected into 4-8 C57Bl/6 mice and stomach bacteria from at least two mice were harvested at 1 week or one month. Semi-random PCR was used to amplify and label the DNA next to the transposon insertion from the input (Cy3) and output pool (Cy5) genomic DNA for each array. Two arrays were done per mouse. One array labeled from the left side of transposon (primers S, 2C) and one array labeled from the right side of the transposon (primers N3, 2C). Transposon insertions were defined by spots with signal four standard deviations above background in both arrays. We also counted insertions where two adjacent gene spots (after arranging the data in genome order) gave signal from the two different sides of the transposon (but not both).
Project description:Microarray Tracking of transposon mutants for a H. pylori mouse colonization screen described in Baldwin DN et al. 2007, I&I, 75(2):??, doi:10.1128/IAI.01176-06. Screen in NSH79 H. pylori strain background. Original 2000 clone transposon library was plated and patched to make 25 pools of 48 clones. Clones were infected into 4-8 C57Bl/6 mice and stomach bacteria from at least two mice were harvested at 1 week or one month. Semi-random PCR was used to amplify and label the DNA next to the transposon insertion from the input (Cy3) and output pool (Cy5) genomic DNA for each array. Two arrays were done per mouse. One array labeled from the left side of transposon (primers S, 2C) and one array labeled from the right side of the transposon (primers N3, 2C). Transposon insertions were defined by spots with signal four standard deviations above background in both arrays. We also counted insertions where two adjacent gene spots (after arranging the data in genome order) gave signal from the two different sides of the transposon (but not both).
Project description:TC1: gastric epithelial (AGS) cells infected with wild type H. pylori (G27) and isogenic mutants in cagA and vacA for 0, 0.5, 3, 6, and 12 hours. Total RNA was used to make single stranded Cy5 labelled probe and compared to Cy3 labelled probe from uninfected AGS cells. Hybridizations of G27 (trial 4) and cagA- (trial 3) timecourses were done in parallel. A technical replicate of the G27 time course (trial 5) and hybridization of vacA- (trial 3) time course were done in parallel. The cagA 6 and 12 hour time points were technically replicated (trial 4) (the cagA 6 hour sample of trial 3 was lost). TC2: Biological replication and expansion of TC1, using more isogenic mutants and timepoints. AGS cells were mock infected, infected with G27, and isogenic mutants in cagN, cagA, cagE, and a deletion of the cag PAI for 0. 1, 3, 6, 12, and 24 hours. Probe synthesis and hybridization was done as in TC1. Note: there may have been a sample mix-up with PAI 12, swapping it with G27 or cagN 12. Groups of assays that are related as part of a time series. Keywords: time_series_design
Project description:Chronic infection of the human stomach with Helicobacter pylori leads to a variety of pathologic sequelae including peptic ulcer and gastric cancer, resulting in significant human morbidity and mortality. Several genes have been implicated in disease related to H. pylori infection including the vacuolating cytotoxin and the cag pathogenicity island. Other factors important for establishment and maintenance of infection include urease enzyme production, motility, iron uptake and stress response. We utilized a C57BL/6 mouse infection model to query a collection of 2400 transposon mutants in two different bacterial strain backgrounds for H. pylori genetic loci contributing to colonization of the stomach. Microarray based tracking of transposon mutants allowed us to monitor the behavior of transposon insertions in 758 different gene loci. Of the loci measured 223 (29%) had a predicted colonization defect. These include previously described H. pylori virulence genes, genes implicated in virulence in other pathogenic bacteria and 81 hypothetical proteins. We have retested 10 previously uncharacterized candidate colonization gene loci by making independent null alleles and confirmed their colonization phenotype using competition experiments and determination of the dose required for 50% infection. Of the genetic loci retested, 60% have strain specific colonization defects while 40% had phenotypes in both strain backgrounds for infection, highlighting the profound effect of H. pylori strain variation on the pathogenic potential of this organism. This SuperSeries is composed of the SubSeries listed below.