title: Frequent occurrence of multidrug-resistant CC17 Enterococcus faecium among clinical isolates in Sweden.
abstract: OBJECTIVE
  To screen for the globally spread cluster of Enterococcus faecium, clonal complex 17 (CC17) and characterize the genetic profile of Swedish clinical Ent. faecium isolates.
  
  
  METHODS
  A total of 203 consecutive isolates collected from 2004 to 2007 from patients with bacteraemia in Sweden. All isolates were genotyped using multiple-locus variable-number tandem repeat analysis (MLVA) and 20 isolates representing different MLVA types (MT) were chosen for multilocus sequence typing (MLST). Minimal inhibitory concentrations against clinically relevant antibiotics were determined with agar dilution. Presence of the virulence genes esp and hyl was investigated using PCR.
  
  
  RESULTS
  A total of 65% (n = 109) of all isolates belonged to MT-1, and the second most common MLVA type was MT-159 (13%, n = 21). MLST analysis confirmed the presence of CC17 during the entire study period. The number of isolates resistant to gentamicin and vancomycin, as well as the presence of hyl, increased significantly during the investigation period.
  
  
  CONCLUSIONS
  The present study demonstrates that nosocomial infections caused by Ent. faecium CC17 are commonly occurring in Sweden.
  
  
  CONCLUSIONS
  This is the first report of CC17 Ent. faecium in Sweden. The increase of antibiotic resistance and virulence indicates that these strains are further adapting to the hospital environment.
authors.affiliation: Division of Clinical Microbiology, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Billström
authors.forename: J
authors.initials: J
authors.lastname: Top
authors.forename: C
authors.initials: C
authors.lastname: Edlund
authors.forename: B
authors.initials: B
authors.lastname: Lund
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics; D003428:Cross Infection / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D016908:Gram-Positive Bacterial Infections / Q000235:genetics / Q000382:microbiology*; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D013548:Sweden
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008565:Membrane Proteins; C116707:enterococcal surface protein, esp; D006821:Hyaluronoglucosaminidase