title: Molecular epidemiology and characterization of an outbreak causing Klebsiella pneumoniae clone carrying chromosomally located bla(CTX-M-15) at a German University-Hospital.
abstract: BACKGROUND
  Multi-drug resistant Klebsiella pneumoniae strains are a common cause of health care associated infections worldwide. Clonal spread of Klebsiella pneumoniae isolates carrying plasmid mediated CTX-M-15 have been commonly reported. Limited data is available regarding dissemination of chromosomally encoded CTX-M-15 in Klebsiella pneumoniae worldwide.
  
  
  RESULTS
  We examined 23 non-repetitive ESBL-producing Klebsiella pneumoniae strains isolated from clinical specimens over a period of 4 months in a German University Hospital. All isolates were characterized to determine their genetic relatedness using Pulsed-Field Gel Electrophoresis (PFGE) and Multi Locus Sequence Typing (MLST). PFGE revealed three clusters (B1, B2, and B3) with a sub-cluster (A3) comprising of 10 isolates with an identical PFGE pattern. All strains of the cluster B3 with similar PFGE patterns were typed as ST101, indicating an outbreak situation. The ESBL allele bla CTX-M-15 was identified in 16 (69.6 %) of all isolates, including all of the outbreak strains. Within the A3 sub-cluster, the CTX-M-15 allele could not be transferred by conjugation. DNA hybridization studies suggested a chromosomal location of bla CTX-M-15. Whole genome sequencing located CTX-M-15 within a complete ISEcp-1 transposition unit inserted into an ORF encoding for a putative membrane protein. PCR-based analysis of the flanking regions demonstrated that insertion into this region is unique and present in all outbreak isolates.
  
  
  CONCLUSIONS
  This is the first characterization of a chromosomal insertion of bla CTX-M-15 in Klebsiella pneumonia ST101, a finding suggesting that in Enterobacteriaceae, chromosomal locations may also act as reservoirs for the spread of bla CTX-M-15 encoding transposition units.
authors.affiliation: Catholic University of Health and Allied Sciences, Weill Bugando School of Medicine Box, 1464, Mwanza, Tanzania. mshana72@yahoo.com.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Mshana
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, , Schubertstrasse 81, 35392, Giessen, Germany. moritz.fritzenwanker@mikrobio.med.uni-giessen.de.|German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Schubertstrasse 81, 35392, Giessen, Germany. moritz.fritzenwanker@mikrobio.med.uni-giessen.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Fritzenwanker
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, , Schubertstrasse 81, 35392, Giessen, Germany. linda.falgenhauer@mikrobio.med.uni-giessen.de.|German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Schubertstrasse 81, 35392, Giessen, Germany. linda.falgenhauer@mikrobio.med.uni-giessen.de.
authors.forename: Linda
authors.initials: L
authors.lastname: Falgenhauer
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, , Schubertstrasse 81, 35392, Giessen, Germany. eugen.domann@mikrobio.med.uni-giessen.de.|German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Schubertstrasse 81, 35392, Giessen, Germany. eugen.domann@mikrobio.med.uni-giessen.de.
authors.forename: Eugen
authors.initials: E
authors.lastname: Domann
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, , Schubertstrasse 81, 35392, Giessen, Germany. torsten.hain@mikrobio.med.uni-giessen.de.|German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Schubertstrasse 81, 35392, Giessen, Germany. torsten.hain@mikrobio.med.uni-giessen.de.
authors.forename: Torsten
authors.initials: T
authors.lastname: Hain
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, , Schubertstrasse 81, 35392, Giessen, Germany. trinad.chakraborty@mikrobio.med.uni-giessen.de.|German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Schubertstrasse 81, 35392, Giessen, Germany. trinad.chakraborty@mikrobio.med.uni-giessen.de.
authors.forename: Trinad
authors.initials: T
authors.lastname: Chakraborty
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, , Schubertstrasse 81, 35392, Giessen, Germany. can.imirzalioglu@mikrobio.med.uni-giessen.de.|German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Schubertstrasse 81, 35392, Giessen, Germany. can.imirzalioglu@mikrobio.med.uni-giessen.de.
authors.forename: Can
authors.initials: C
authors.lastname: Imirzalioglu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002876:Chromosomes, Bacterial / Q000235:genetics*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial; D005858:Germany / Q000453:epidemiology; D006785:Hospitals, University; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases