Project description:Escherichia coli is the most well-studied bacterium and a common colonizer of the lower mammalian gastrointestinal tract. We report here the complete genome sequence of the original Escherichia coli isolate, strain NCTC86, which was described by Theodor Escherich, for whom the genus is named.
Project description:These E. coli strains were grown with various signaling molecules and the expression profiles were determined. Keywords: addition of quorum and host hormone signals
Project description:Escherichia coli strain FEX669 was isolated from retail ground chicken and shown to contain the extraintestinal pathogenic E. coli (ExPEC) virulence genes sfaD, focC, and iutA Because this presumptive ExPEC strain was isolated from a retail food item and it was a weak biofilm former, it was characterized using whole-genome sequencing using the PacBio RS II platform. Genomic analysis showed that the FEX669 chromosome is 4,973,943?bp long, with a GC content of 50.47%, and is accompanied by a ColV plasmid that is 237,102?bp long, with a GC content of 50.49%.
Project description:Escherichia coli species exhibits a high genomic diversification from evolution, mobile genetic elements and recombination. An environmental E. coli isolate, 'JHI_5025' from a crop trial appeared to be clonally related to the historical reference isolate E. coli K-12 strain 'MG1655', warranting further genomic analysis. Their genomes share an average nucleotide identity of 99.74% and whole genome alignment showed little rearrangement of the JHI_5025 sequence compared to the reference. Five genomic islands not in the reference aligned to other sequences in the Enterobacteriaceae. Isolate JHI_5025 contained E. coli K-12 F plasmid sequence and at least one complete prophage sequence. The genome and comparison dataset provides utility of E. coli JHI_5025 as a representative contemporary genetic mimic of a well-known and much used workhorse strain.
Project description:In order to understand the impact of genetic variants on transcription and ultimately in changes in observed phenotypes we have measured transcript levels in an Escherichia coli strains collection, for which genetic and phenotypic data has also been measured.
Project description:Escherichia coli Mt1B1, a mouse isolate, is a facultative anaerobic bacterium which was shown to counteract Salmonella enterica serovar Typhimurium infection in a mouse model. In the present study, we describe the complete genome sequence of E. coli Mt1B1, composed of a 5.1-Mb chromosome and a 62.6-kb plasmid.
Project description:Enterotoxigenic Escherichia coli (ETEC) is an important pathogenic variant (pathovar) of E. coli in developing countries from a human health perspective, causing significant morbidity and mortality. Previous studies have examined specific regulatory networks in ETEC, although little is known about the global effects of inter- and intrakingdom signaling on the expression of virulence and colonization factors in ETEC. In this study, an E. coli/Shigella pan-genome microarray, combined with quantitative reverse transcriptase PCR (qRT-PCR) and RNA sequencing (RNA-seq), was used to quantify the expression of ETEC virulence and colonization factors. Biologically relevant chemical signals were combined with ETEC isolate E24377A during growth in either Luria broth (LB) or Dulbecco's modified Eagle medium (DMEM), and transcription was examined during different phases of the growth cycle; chemical signals examined included glucose, bile salts, and preconditioned media from E. coli/Shigella isolates. The results demonstrate that the presence of bile salts, which are found in the intestine and thought to be bactericidal, upregulates the expression of many ETEC virulence factors, including heat-stable (estA) and heat-labile (eltA) enterotoxin genes. In contrast, the ETEC colonization factors CS1 and CS3 were downregulated in the presence of bile, consistent with findings in studies of other enteric pathogens. RNA-seq analysis demonstrated that one of the most differentially expressed genes in the presence of bile is a unique plasmid-encoded AraC-like transcriptional regulator (peaR); other previously unknown genetic elements were found as well. These results provide transcriptional targets and putative mechanisms that should help improve understanding of the global regulatory networks and virulence expression in this important human pathogen.
Project description:Understanding how genetic variation contributes to phenotypic differences is a fundamental question in biology. Combining high-throughput gene function assays with mechanistic models of the impact of genetic variants is a promising alternative to genome-wide association studies. Here we have assembled a large panel of 696 Escherichia coli strains, which we have genotyped and measured their phenotypic profile across 214 growth conditions. We integrated variant effect predictors to derive gene-level probabilities of loss of function for every gene across all strains. Finally, we combined these probabilities with information on conditional gene essentiality in the reference K-12 strain to compute the growth defects of each strain. Not only could we reliably predict these defects in up to 38% of tested conditions, but we could also directly identify the causal variants that were validated through complementation assays. Our work demonstrates the power of forward predictive models and the possibility of precision genetic interventions.
Project description:Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain.
Project description:Escherichia coli strain BL21 is one of the widely used bacterial hosts for high-level recombinant protein production and for other applications. Here, we present the complete genome sequence of a commercial version of the Escherichia coli BL21 strain.