title: Different IS629 transposition frequencies exhibited by Escherichia coli O157:H7 strains in the stepwise evolutionary model.
abstract: The insertion sequence IS629, which is highly prevalent in Escherichia coli O157:H7 genomes, was found to be absent in O157:H- strains, which are on a divergent pathway in the emergence of O157:H7. Although O157:H- is deficient in IS629, it permits IS629 transposition, with an excision frequency higher than that of ancestral O55:H7 strains but significantly lower than that of pathogenic O157:H7 strains.
authors.affiliation: Division of Microbiology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740, USA.
authors.forename: Lydia V
authors.initials: LV
authors.lastname: Rump
authors.forename: Markus
authors.initials: M
authors.lastname: Fischer
authors.forename: Narjol
authors.initials: N
authors.lastname: González-Escalona
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D004251:DNA Transposable Elements / Q000235:genetics*; D019453:Escherichia coli O157 / Q000201:enzymology* / Q000235:genetics*; D005822:Genetic Vectors / Q000235:genetics; D016680:Genome, Bacterial; D016133:Polymerase Chain Reaction; D019895:Transposases / Q000235:genetics*
chemical_list: D000942:Antigens, Bacterial; D004251:DNA Transposable Elements; C022863:H antigen; D019895:Transposases