Topic
Escherichia coli
About: Escherichia coli is a research topic. Over the lifetime, 59041 publications have been published within this topic receiving 2050337 citations. The topic is also known as: E. coli & E coli jdj.
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TL;DR: I2 and anti-Escherichia coli outer membrane porin C are associated with Crohn's disease phenotypes, and patients with the highest level of serum reactivity toward an increasing number of microbiota have the greatest frequency of strictures, internal perforations, and small bowel surgery.
508 citations
TL;DR: Phylogenetic analysis reveals that old lineages of E. coli have acquired the same virulence factors in parallel, including a pathogenicity island involved in intestinal adhesion, a plasmid-borne haemolysin, and phage-encoded Shiga toxins, indicating that natural selection has favoured an ordered acquisition of genes and the progressive build-up of molecular mechanisms that increase virulence.
Abstract: The mechanisms underlying the evolution and emergence of new bacterial pathogens are not well understood. To elucidate the evolution of pathogenic Escherichia coli strains, here we sequenced seven housekeeping genes to build a phylogenetic tree and trace the history of the acquisition of virulence genes. Compatibility analysis indicates that more than 70% of the informative sites agree with a single phylogeny, suggesting that recombination has not completely obscured the remnants of ancestral chromosomes1,2,3. On the basis of the rate of synonymous substitution for E. coli and Salmonella enterica (4.7 × 10-9 per site per year3), the radiation of clones began about 9 million years ago and the highly virulent pathogen responsible for epidemics of food poisoning, E. coli O157:H7, separated from a common ancestor of E. coli K-12 as long as 4.5 million years ago. Phylogenetic analysis reveals that old lineages of E. coli have acquired the same virulence factors in parallel, including a pathogenicity island involved in intestinal adhesion, a plasmid-borne haemolysin, and phage-encoded Shiga toxins. Such parallel evolution indicates that natural selection has favoured an ordered acquisition of genes and the progressive build-up of molecular mechanisms that increase virulence.
506 citations
506 citations
TL;DR: The activating effects of PLP and Fe+++ on these earlier preparations remain unexplained but were partially due to stabilizing effects on the enzyme under the assay conditions then in use, and hence provide no evidence for a role ofPLP in action of the enzyme.
Abstract: 'I Martin, R. G., and B. N. Ames, J. Biol. Chem., 236, 1372 (1961). 15 For references to individual enzymes, see Snell, E. E., in The Mechanism of Action of Water Soluble Vitamins, Ciba Foundation Study Group No. 11, ed. A. V. E8. de Reuck and A. O'Connor (London: Churchill, 1961), pp. 18-37. 16 Under the same conditions PLP was observed to interact with serum albumin with appearance of absorption maxima at 332 and 415 m/A, as described by W. B. Dempsey and H. N. Christensen [J. Biol. Chem., 237, 1113 (1962)]. 17 The activating effects of PLP and Fe+++ on these earlier preparations9 remain unexplained but were partially due to stabilizing effects on the enzyme under the assay conditions then in use. They could be duplicated by Tweens, and hence provide no evidence for a role of PLP in action of the enzyme. Neither crude nor pure preparations of enzyme prepared and assayed by the present procedure show these effects. 18 Rabinowitz, J. C., and E. E. Snell, J. Biol. Chem., 176, 1157 (1948). 19 Shore, P. A., A. Burkhalter, and V. H. Cohn, Jr., J. Pharm. Exptl. Therap., 127, 182 (1959). 20 Du Vigneaud, V., and 0. K. Behrens, J. Biol. Chem., 117, 27 (1937). 21 Wallach, O., Ber., 15, 644 (1882).
505 citations
TL;DR: This chapter will present known molecular mechanisms underlying biofilm development in both commensal and pathogenic E. coli.
Abstract: Escherichia coli is a predominant species among facultative anaerobic bacteria of the gastrointestinal tract. Both its frequent community lifestyle and the availability of a wide array of genetic tools contributed to establish E. coli as a relevant model organism for the study of surface colonization. Several key factors, including different extracellular appendages, are implicated in E. coli surface colonization and their expression and activity are finely regulated, both in space and time, to ensure productive events leading to mature biofilm formation. This chapter will present known molecular mechanisms underlying biofilm development in both commensal and pathogenic E. coli.
503 citations