title: The pathogenicity island-associated K15 capsule determinant exhibits a novel genetic structure and correlates with virulence in uropathogenic Escherichia coli strain 536.
abstract: The K15 capsule determinant of uropathogenic Escherichia coli strain 536 (O6:K15:H31) is part of a novel 79.6-kb pathogenicity island (PAI) designated PAI V536 that is absent from the genome of nonpathogenic E. coli K-12 strain MG1655. PAI V536 shows typical characteristics of a composite PAI that is associated with the pheV tRNA gene and contains the pix fimbriae determinant as well as genes coding for a putative phosphoglycerate transport system, an autotransporter protein, and hypothetical open reading frames. A gene cluster coding for a putative general secretion pathway system, together with a kps(K15) determinant, is localized downstream of a truncated pheV gene ('pheV) also present in this chromosomal region. The distribution of genes present on PAI V536 was studied by PCR in different pathogenic and nonpathogenic E. coli isolates of various sources. Analysis of the 20-kb kps locus revealed a so far unknown genetic organization. Generally, the kps(K15) gene cluster resembles that of group 2 and 3 capsules, where two conserved regions (regions 1 and 3) are located up- or downstream of a highly variable serotype-specific region (region 2). Interestingly, recombination of a group 2 and 3 determinant may have been involved in the evolution of the K15 capsule-encoding gene cluster. Expression of the K15 capsule is important for virulence in a murine model of ascending urinary tract infection but not for serum resistance of E. coli strain 536.
authors.affiliation: Institut für Molekulare Infektionsbiologie, Universität Würzburg, Würzburg, Germany.
authors.forename: György
authors.initials: G
authors.lastname: Schneider
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dobrindt
authors.forename: Holger
authors.initials: H
authors.lastname: Brüggemann
authors.forename: Gábor
authors.initials: G
authors.lastname: Nagy
authors.forename: Britta
authors.initials: B
authors.lastname: Janke
authors.forename: Gabriele
authors.initials: G
authors.lastname: Blum-Oehler
authors.forename: Carmen
authors.initials: C
authors.lastname: Buchrieser
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gottschalk
authors.forename: Levente
authors.initials: L
authors.lastname: Emödy
authors.forename: Jörg
authors.initials: J
authors.lastname: Hacker
mesh_terms: D000818:Animals; D016667:Bacterial Capsules / Q000096:biosynthesis* / Q000235:genetics; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D044404:Genomic Islands / Q000235:genetics*; D051379:Mice; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D014552:Urinary Tract Infections / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D012343:RNA, Transfer