title: A novel integrative and conjugative element (ICE) of Escherichia coli: the putative progenitor of the Yersinia high-pathogenicity island.
abstract: Diversification of bacterial species and pathotypes is largely caused by horizontal transfer of diverse DNA elements such as plasmids, phages and genomic islands (e.g. pathogenicity islands, PAIs). A PAI called high-pathogenicity island (HPI) carrying genes involved in siderophore-mediated iron acquisition (yersiniabactin system) has previously been identified in Yersinia pestis, Y. pseudotuberculosis and Y. enterocolitica IB strains, and has been characterized as an essential virulence factor in these species. Strikingly, an orthologous HPI is a widely distributed virulence determinant among Escherichia coli and other Enterobacteriaceae which cause extraintestinal infections. Here we report on the HPI of E. coli strain ECOR31 which is distinct from all other HPIs described to date because the ECOR31 HPI comprises an additional 35 kb fragment at the right border compared to the HPI of other E. coli and Yersinia species. This part encodes for both a functional mating pair formation system and a DNA-processing region related to plasmid CloDF13 of Enterobacter cloacae. Upon induction of the P4-like integrase, the entire HPI of ECOR31 is precisely excised and circularised. The HPI of ECOR31 presented here resembles integrative and conjugative elements termed ICE. It may represent the progenitor of the HPI found in Y. pestis and E. coli, revealing a missing link in the horizontal transfer of an element that contributes to microbial pathogenicity upon acquisition.
authors.affiliation: Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Lehrstuhl für Bakteriologie, Pettenkoferstr. 9a, 80336 Munich, Germany. schubert@pk-i.med.uni-muenchen.de
authors.forename: Sören
authors.initials: S
authors.lastname: Schubert
authors.forename: Severin
authors.initials: S
authors.lastname: Dufke
authors.forename: Johanna
authors.initials: J
authors.lastname: Sorsa
authors.forename: Jürgen
authors.initials: J
authors.lastname: Heesemann
mesh_terms: D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D022761:Gene Transfer, Horizontal; D044404:Genomic Islands; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D015007:Yersinia / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*