title: In vitro activity of tigecycline and molecular characterization of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates from a university hospital in south-western Germany.
abstract: BACKGROUND
  Extended-spectrum β-lactamase (ESBL)-producing organisms are spreading worldwide in hospital and community settings.
  
  
  METHODS
  A total of 328 unduplicated ESBL-producing Enterobacteriaceae isolated in 2008 and 2009 at the University Hospital of Tübingen were analysed retrospectively.
  
  
  RESULTS
  Escherichia coli (n = 253) and Klebsiella spp. (n = 46) were the most frequent ESBL-producing species. The ESBL rates among E. coli and Klebsiella spp. increased from 3.8 and 2.1%, respectively, in 2008, to 5.2 and 2.4%, respectively, in 2009. Two E. coli and 3 Klebsiella pneumoniae ESBL producers were non-susceptible to ertapenem, most likely due to loss of porins. Antimicrobial susceptibility testing of selected, molecularly characterized ESBL producers revealed susceptibility to tigecycline among 97.9% (191/195) of the E. coli and 78.8% (26/33) of the K. pneumoniae isolates. PCR analysis and sequencing showed the presence of CTX-M-type enzymes in 91.3% of the E. coli and 87.9% of the K. pneumoniae isolates, whereby bla(CTX-M-15) was the most frequent ESBL gene both in E. coli (50.0%) and K. pneumoniae (51.5%). Only 7 single cases of potential patient-to-patient transmissions of E. coli strains were observed.
  
  
  CONCLUSIONS
  Our data suggest that the increase in ESBL-producing E. coli and K. pneumoniae isolates at our hospital is mainly caused by growing import of Enterobacteriaceae harbouring CTX-M-type ESBLs.
authors: Institute of Medical Microbiology and Hygiene, Eberhard Karls University of Tübingen, Tübingen, Germany.
authors: Matthias
authors: M
authors: Wienke
authors: Yvonne
authors: Y
authors: Pfeifer
authors: Patrick
authors: P
authors: Weissgerber
authors: Matthias
authors: M
authors: Marschal
authors: Ingo B
authors: IB
authors: Autenrieth
authors: Sabine
authors: S
authors: Gröbner
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology; D000077727:Ertapenem; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D005858:Germany; D006785:Hospitals, University; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D015995:Prevalence; D012189:Retrospective Studies; D000078304:Tigecycline; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D004269:DNA, Bacterial; D047090:beta-Lactams; D000078304:Tigecycline; D001618:beta-Lactamases; D008911:Minocycline; D000077727:Ertapenem