Campylobacter jejuni comparative genome: Control strain 11168 vs. strain NW
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ABSTRACT: Gene content comparison of control C.j. strain 11168 which colonizes and causes disease in a murine model versus strain NW which colonizes but does not elicit disease symptomology in the mouse model. Keywords: DNA/DNA comparison Two genome comparison of disease strain versus non disease strain of C.j., Biological replicates - 2, independently grown and harvested, Technical replicates 2, also independent, 3 ORF replicates per array.
Project description:Gene content comparison of control C. jejuni subsp. jejuni strain 11168 which colonizes and causes disease in C57BL/6 IL-10-/- mice versus C. jejuni strains D6844, D6845, D6846, D6847, D6848, D6849, D0121, D0835, D2586, D2600,33560 and NW in the C57BL/6 IL-10-/- mice. Keywords: DNA/DNA comparison Two genome comparison of disease strain versus non disease strain of C.j., 4 Biological replicates - 2 of which were dye swaps
Project description:Gene content comparison of control C.j. strain 11168 which colonizes and causes disease in a murine model versus strain NW which colonizes but does not elicit disease symptomology in the mouse model. Keywords: DNA/DNA comparison
Project description:In this study, RNA-seq was used to compare the transcriptomes of Listeria monocytogenes 10403S::ÎBCHL Prha-sigH and ÎBCHL Prha. RNA-seq was performed on ÎBCHL Prha-sigH and ÎBCHL Prha RNA samples representing three independent biological replicates at log phase in Brain Heart Infusion (BHI) broth under rhamnose induction. Indexed and purified cDNA libraries (6 libraries including 3 replicates for 2 strains) were loaded together onto an independent flow cell without any other samples; sequencing was carried out by running Hiseq 2500 (single-end, 150-bp per read). Reads alignment was carried out using the Burrows-Wheeler Aligner (BWA). Differential expression of genes in different strains was statistically assessed using the BaySeq method. To identify sigH-dependent promoters, a new method of moving sliding windows of 50 nt along the whole genome was used to compare the normalized RNA-seq coverage (NRC) between the two strains. Using the standard whole gene differential expression analysis, significant upregulation of 5 genes in 4 operons was found in the sigH overexpressing strain. While with the sliding windiow analysis, 2 additional ÏH-dependent promoters were identified. Our results show that three ÏH-dependent transcritption units that encode competence proteins, including the comEABC , comGABCDEFG and coiA. Transcriptome profiles of L. monocytogenes 10403S::ÎBCHL Prha-sigH and ÎBCHL Prha were generated by deep sequencing, in triplicate, using Illumina Hiseq 2500.
Project description:Clostridium difficile is a gram-positive, spore-forming enteric anaerobe which can infect humans and a wide variety of animal species. Recently, the incidence and severity of human C. difficile infection has markedly increased. In this study, we evaluated the genomic content of 73 C. difficile strains isolated from humans, horses, cattle, and pigs by comparative genomic hybridization with microarrays containing coding sequences from C. difficile strains 630 and QCD-32g58. The sequenced genome of C. difficile strain 630 was used as a reference to define a candidate core genome of C. difficile and to explore correlations between host origins and genetic diversity. Approximately 16% of the genes in strain 630 were highly conserved among all strains, representing the core complement of functional genes defining C. difficile. Absent or divergent genes in the tested strains were distributed across the entire C. difficile 630 genome and across all the predicted functional categories. Interestingly, certain genes were conserved among strains from a specific host species, but divergent in isolates with other host origins. This information provides insight into the genomic changes which might contribute to host adaptation. Due to a high degree of divergence among C. difficile strains, a core gene list from this study offers the first step toward the construction of diagnostic arrays for C. difficile.investigated by determining changes in transcript profiles when aerobic steady-state cultures were depleted of air. Dye-swap experiments with genomic DNA of tested and reference strains 8383cy3.gpr- Cy3 – test, Cy5 – reference 8384cy3.gpr- Cy3 – test, Cy5 – reference 8384cy5.gpr- Cy3 – reference, Cy5 – test 8385cy3.gpr- Cy3 – test, Cy5 – reference 8385cy5.gpr- Cy3 – reference, Cy5 – test 8386cy3.gpr- Cy3 – test, Cy5 – reference 8525cy3.gpr- Cy3 – test, Cy5 – reference 8525cy5.gpr- Cy3 – reference, Cy5 – test 8527cy5.gpr- Cy3 – reference, Cy5 – test 8529cy5.gpr- Cy3 – reference, Cy5 – test 8531cy3.gpr- Cy3 – test, Cy5 – reference 8531cy5.gpr- Cy3 – reference, Cy5 – test 8533cy3.gpr- Cy3 – test, Cy5 – reference 8533cy5.gpr- Cy3 – reference, Cy5 – test 8596cy3.gpr- Cy3 – test, Cy5 – reference 8596cy5.gpr- Cy3 – reference, Cy5 – test 8694cy3.gpr- Cy3 – test, Cy5 – reference 8694cy5.gpr- Cy3 – reference, Cy5 – test 2 GPR files per Sample record except for 4 Sample records (GSM480414, GSM480417, GSM480419, and GSM480420) which have 1 GPR file each 4 GPR file for those Sample records are lost
Project description:Introduction Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are increasingly isolated, with USA300-0114 being the predominant clone in the USA. Comparative whole genome sequencing of USA300 isolates collected in 2002, 2003 and 2005 showed a limited number of single nucleotide polymorphisms and regions of difference. This suggests that USA300 has undergone rapid clonal expansion without great genomic diversification. However, whole genome comparison of CA-MRSA has been limited to isolates belonging to USA300. The aim of this study was to compare the genetic repertoire of different CA-MRSA clones with that of HA-MRSA from the USA and Europe through comparative genomic hybridization (CGH) to identify genetic clues that may explain the successful and rapid emergence of CA-MRSA. Materials and Methods Hierarchical clustering based on CGH of 48 MRSA isolates from the community and nosocomial infections from Europe and the USA revealed dispersed clustering of the 19 CA-MRSA isolates. This means that these 19 CA-MRSA isolates do not share a unique genetic make-up. Only the PVL genes were commonly present in all CA-MRSA isolates. However, 10 genes were variably present among 14 USA300 isolates. Most of these genes were present on mobile elements. Conclusion The genetic variation present among the 14 USA300 isolates is remarkable considering the fact that the isolates were recovered within one month and originated from a confined geographic area, suggesting continuous evolution of this clone. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-108 target=_blank>BuG@Sbase</a>
Project description:DNA microarray analysis was used to compare the differential gene-expression profiles between Leptospira interrogans serovar Lai type strain 56601 and its corresponding attenuated strain IPAV. A 22 kb genomic island covering a cluster of 34 genes (LA0186 to LA0219) was actively expressed in both strains but concomitantly up-expressed in strain 56601 in contrast to that of IPAV. RT-PCR assays proved that the gene cluster comprised five transcripts. Gene annotation of this cluster revealed characteristics of a putative prophage-like remnant with at least 8 out of 34 CDSs encoding prophage-like proteins, of which, LA0195 is probably a putative prophage CI-like regulator. The transcription initiation activities of putative promoter-regulatory sequences of transcripts I, II and III, all proximal to LA0195, were further analyzed in the Escherichia coli promoter probe vector pKK232-8 by assaying the reporter CAT enzyme activities. The strong promoter activities of both transcripts I and II indicated by the E. coli CAT assay were well correlated with the in vitro sequence-specific binding of the recombinant LA0195 protein to the corresponding promoter probes detected by the electrophoresis mobility shift assay. On the other hand, the promoter activity of transcript III was very low in E. coli and failed to show active binding to LA0195 in vitro. These results suggested that LA0195 is likely involved in the transcription of transcripts I and II. However, the identical complete DNA sequences of this prophage remnant from these two strains strongly suggests that possible regulatory factors or signal transduction systems resided outside of this region within the genome maybe responsible for the differential expression profiling in these two strains. Keywords: Differential expression of L.interrogans 56601 and IPAV in 37°C The microarray chip was prepared as previously described (42). In brief, the 3528 protein coding sequences (CDSs) successfully amplified by PCR were printed in triplicate on the slides as probes. Three expression profiling experiments were performed via reverse transcription using Superscript (Invitrogen) and with one experiment having the cDNA of IPAV labeled by Cy3 and of 56601 labeled by Cy5, while the other two having the cDNA of 56601 labeled by Cy3 and of IPAV labeled by Cy5. The unincorporated dye was removed using a QIAquick Nucleotide Removal Kit (Qiagen) as specified by the manufacturer's protocol. Samples were hybridized at 42°C for 16h, and then washed as described in the manual. Hybridization experiments were performed in triplicate using cDNA derived from three different cultures of virulent strain 56601 and avirulent strain IPAV grown at 37°C. The hybridized slides were scanned and analyzed by Tiffsplit (Agilent) to calculate the signal intensities and to determine the presence or absence of each CDS. The data were then normalized, and their backgrounds were defined using GeneSpring 4.0 (Silicon Genetics). The GeneSpring software was used to further analyze the transcription patterns. To identify genes with significantly altered expression levels, cutoff values for expression level ratios 1.5 were used to filter genes with changes (n-fold) greater than ±1.5 in three independent biological samples (27, 48, 50). Studentâs t test analysis of variance was used to compare the mean expression levels of the test and reference samples. Genes with significant differential expression levels (P < 0.05) were selected.
Project description:Gene content comparison of control C. jejuni subsp. jejuni strain 11168 which colonizes and causes disease in C57BL/6 IL-10-/- mice versus C. jejuni strains D6844, D6845, D6846, D6847, D6848, D6849, D0121, D0835, D2586, D2600,33560 and NW in the C57BL/6 IL-10-/- mice. Keywords: DNA/DNA comparison
Project description:Escherichia coli spans a genetic continuum from enteric strains to several phylogenetically distinct, atypical lineages that are rare in humans, but more common in extra-intestinal environments. To investigate the link between gene regulation, phylogeny and diversification in this species, we analyzed global gene expression profiles of four strains representing distinct evolutionary lineages, including a well-studied laboratory strain, a typical commensal (enteric) strain and two environmental strains. RNA-Seq was employed to compare the whole transcriptomes of strains grown under batch, chemostat and starvation conditions. Highly differentially expressed genes showed a significantly lower nucleotide sequence identity compared with other genes, indicating that gene regulation and coding sequence conservation are directly connected. Overall, distances between the strains based on gene expression profiles were largely dependent on the culture condition and did not reflect phylogenetic relatedness. Expression differences of commonly shared genes (all four strains) and E. coli core genes were consistently smaller between strains characterized by more similar primary habitats. For instance, environmental strains exhibited increased expression of stress defense genes under carbon-limited growth and entered a more pronounced survival-like phenotype during starvation compared with other strains, which stayed more alert for substrate scavenging and catabolism during no-growth conditions. Since those environmental strains show similar genetic distance to each other and to the other two strains, these findings cannot be simply attributed to genetic relatedness but suggest physiological adaptations. Our study provides new insights into ecologically relevant gene-expression and underscores the role of (differential) gene regulation for the diversification of the model bacterial species. Four E.coli strains, laboratory strain K12 (MG1655), a commensal model strain (IAI1), a soil-isolated strain (TW11588-Clade IV), and a freshwater-isolated strain (TW09308âClade V) were used. Each strain was grown on a minimal growth medium (Ihssen and Egli, 2004) in three treatment modes: chemostat, batch, and starvation. Cells from batch culture were collected when reaching steady-state. For starvation, the medium flow was stopped during steady-state and bacteria were collected after 4âh.