title: Molecular epidemiology of Enterococcus faecium isolates from an Italian hospital.
abstract: BACKGROUND
  Outbreaks of vancomycin-resistant Enterococcus faecium (VRE) strains is an emerging problem worldwide. Even if still relatively uncommon in European hospitals, infections caused by VRE have also been increasing recently in this continent.
  
  
  METHODS
  In this study, we characterized 50 consecutive VRE and 23 vancomycin-sensitive E. faecium (VSE) isolates collected in an Italian hospital. The presence of the esp gene and that of genes encoding resistance to glycopeptides was investigated by polymerase chain reaction (PCR). All of the isolates were typed by multi-locus sequence typing (MLST), and a selection of them also by pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  We found that all of the VRE and 18 (78%) of the VSE strains belonged to the single clonal complex-17 (CC17). The most represented sequence type (ST) was ST78 (34% of the isolates). When further analyzed by PFGE, ST78 isolates were subdivided into five pulsotypes, four of them closely related. The strong association between the esp gene and CC17 was confirmed. Interestingly, such an association was higher among vancomycin-resistant isolates. Most of the esp-positive isolates (34/46, 74%) encoded Esp4, a rare variant of this protein characterized by the absence of A repeats.
  
  
  CONCLUSIONS
  Our findings underscore the role of the CC17 lineage in the nosocomial spread of VRE and VSE, and its rapid local evolution, underscoring the need for programs designed to provide early detection in order to prevent its spreading among the nosocomial population.
authors.affiliation: Regional Reference Centre for Infectious Diseases, Microbiology and Virology Unit, Azienda Ospedaliera di Padova, Padova, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Fallico
authors.forename: C
authors.initials: C
authors.lastname: Boldrin
authors.forename: A
authors.initials: A
authors.lastname: Grossato
authors.forename: E
authors.initials: E
authors.lastname: Franchin
authors.forename: E
authors.initials: E
authors.lastname: De Canale
authors.forename: T
authors.initials: T
authors.lastname: Tommasini
authors.forename: S G
authors.initials: SG
authors.lastname: Parisi
authors.forename: R
authors.initials: R
authors.lastname: Manganelli
authors.forename: G
authors.initials: G
authors.lastname: Palù
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D007558:Italy; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin