title: Rare emergence of symptoms during long-term asymptomatic Escherichia coli 83972 carriage without an altered virulence factor repertoire.
abstract: OBJECTIVE
  Asymptomatic bacteriuria established by intravesical inoculation of Escherichia coli 83972 is protective in patients with recurrent urinary tract infections. In this randomized, controlled crossover study a total of 3 symptomatic urinary tract infection episodes developed in 2 patients while they carried E. coli 83972. We examined whether virulence reacquisition by symptom isolates may account for the switch from asymptomatic bacteriuria to symptomatic urinary tract infection.
  
  
  METHODS
  We used E. coli 83972 re-isolates from 2 patients in a prospective study and from another 2 in whom symptoms developed after study completion. We phylogenetically classified the re-isolates, and identified the genomic restriction patterns and gene expression profiles as well as virulence gene structure and phenotypes. In vivo virulence was examined in the murine urinary tract infection model.
  
  
  RESULTS
  The fim, pap, foc, hlyA, fyuA, iuc, iroN, kpsMT K5 and malX genotypes of the symptomatic re-isolates remained unchanged. Bacterial gene expression profiles of flagellated symptomatic re-isolates were unique to each host, providing no evidence of common deregulation. Symptomatic isolates did not differ in virulence from the wild-type strain, as defined in the murine urinary tract infection model by persistence, symptoms or innate immune activation.
  
  
  CONCLUSIONS
  The switch from asymptomatic E. coli 83972 carriage to symptomatic urinary tract infection was not explained by reversion to a functional virulence gene repertoire.
authors.affiliation: Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Béla
authors.initials: B
authors.lastname: Köves
authors.affiliation: Institute for Molecular Biology of Infectious Diseases, University of Würzburg, Würzburg, Germany.
authors.forename: Ellaine
authors.initials: E
authors.lastname: Salvador
authors.affiliation: Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Jenny
authors.initials: J
authors.lastname: Grönberg-Hernández
authors.affiliation: Institute for Molecular Biology of Infectious Diseases, University of Würzburg, Würzburg, Germany.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Zdziarski
authors.affiliation: Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Wullt
authors.affiliation: Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Catharina
authors.initials: C
authors.lastname: Svanborg
authors.affiliation: Institute for Molecular Biology of Infectious Diseases, University of Würzburg, Würzburg, Germany; Institute for Hygiene, University of Münster, Münster, Germany. Electronic address: dobrindt@uni-muenster.de.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dobrindt
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D058345:Asymptomatic Infections; D002353:Carrier State / Q000382:microbiology; D018592:Cross-Over Studies; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D051379:Mice; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010641:Phenotype; D011446:Prospective Studies; D012008:Recurrence; D014552:Urinary Tract Infections / Q000235:genetics* / Q000382:microbiology; D014774:Virulence / Q000235:genetics
keywords: ABU; Escherichia coli; IFNγ; IL; K5 capsule; LPS; PMN; UTI; aerobactin; asymptomatic bacteriuria; cnf1; cytotoxic-necrotizing factor1; fyuA; gene expression; hlyA; interferon-γ; interleukin; iroN; iuc; kpsMT K5; lipopolysaccharide; polymorphonuclear leukocyte; salmochelin receptor; urinary bladder; urinary tract infection; urinary tract infections; virulence; wild type; wt; yersiniabactin receptor; α-hemolysin