title: The Toxin-Producing Pathobiont Klebsiella oxytoca Is Not Associated with Flares of Inflammatory Bowel Diseases.
abstract: BACKGROUND
  Alterations in the intestinal microbiota are thought to be involved in the pathogenesis of inflammatory bowel diseases (IBD). Klebsiella oxytoca is an intestinal pathobiont that can produce a cytotoxin (tillivaline).
  
  
  OBJECTIVE
  We aimed to elucidate the pathogenetic relevance of toxin-producing K. oxytoca in patients with IBD flares and investigated the clonal relationship of K. oxytoca isolates from IBD patients using multilocus sequence typing (MLST).
  
  
  METHODS
  Fecal samples of 235 adult IBD patients were collected from January 2008 to May 2009 and were tested for K. oxytoca, C. difficile toxin, and other pathogens by standard microbiological methods. Clinical data and disease activity scores were collected. K. oxytoca isolates were tested for toxin production using cell culture assays. A total of 45 K. oxytoca isolates from IBD patients, healthy, asymptomatic carriers and from patients with antibiotic-associated hemorrhagic colitis in part from our strain collection were tested for their clonal relationship using MLST.
  
  
  RESULTS
  The prevalence of K. oxytoca in IBD overall was 4.7%. Eleven K. oxytoca isolates were detected. Two of 11 isolates were tested positive for toxin production. There was no significant difference in the distribution of K. oxytoca isolates between the groups (active vs. remission in UC and CD). MLST yielded 33 sequence types. K. oxytoca isolates from IBD did not cluster separately from isolates from asymptomatic carriers.
  
  
  CONCLUSIONS
  Our data demonstrate that toxin (tilivalline)-producing K. oxytoca is not associated with IBD flares.
authors.affiliation: Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria. ines.schwetz@medunigraz.at.
authors.forename: Ines
authors.initials: I
authors.lastname: Zollner-Schwetz
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria.|Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Kathrin A T
authors.initials: KA
authors.lastname: Herzog
authors.affiliation: Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Gebhard
authors.initials: G
authors.lastname: Feierl
authors.affiliation: Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Leitner
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Schneditz
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria.
authors.forename: Hanna
authors.initials: H
authors.lastname: Sprenger
authors.affiliation: Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Prattes
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Petritsch
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Heimo
authors.initials: H
authors.lastname: Wenzl
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Kump
authors.affiliation: Institute of Pathology, Medical University of Graz, Graz, Austria.
authors.forename: Gregor
authors.initials: G
authors.lastname: Gorkiewicz
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria.
authors.forename: Ellen
authors.initials: E
authors.lastname: Zechner
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Högenauer
mesh_terms: D000328:Adult; D015373:Bacterial Typing Techniques; D001570:Benzodiazepinones / Q000302:isolation & purification; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000382:microbiology*; D003424:Crohn Disease / Q000175:diagnosis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D018450:Disease Progression; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007422:Intestines / Q000382:microbiology* / Q000473:pathology; D007710:Klebsiella Infections / Q000175:diagnosis / Q000382:microbiology*; D041121:Klebsiella oxytoca / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D001570:Benzodiazepinones; D004269:DNA, Bacterial; C093067:tilivalline
keywords: IBD; Klebsiella oxytoca; MLST; Toxin