title: Molecular epidemiology of meticillin-resistant Staphylococcus aureus in Italian cystic fibrosis patients: a national overview.
abstract: BACKGROUND
  The genetic background, transmissibility and virulence of MRSA have been poorly investigated in the cystic fibrosis (CF) population. The aim of this multicentre study was to analyse MRSA strains isolated from CF patients attending nine Italian CF care centres during a two-year period (2004-2005). All CF patients infected by MRSA were included.
  
  
  METHODS
  Antibiotic susceptibility testing, SCCmec typing, Panton-Valentine Leukocidin (PVL) production, and Multi Locus Sequence Typing (MLST) analysis were carried out on collected isolates (one strain per patient).
  
  
  RESULTS
  One hundred and seventy-eight strains isolated from 2360 patients attending the participating centres were analysed. We detected 56 (31.4%) SCCmec IV PVL-negative strains, with a resistance rate of 80.3% to clindamycin and of 14.5% to trimethoprim/sulphamethoxazole. MLST analysis showed that many isolates belonged to known epidemic lineages. The largest clone grouping of 29 isolates from 6 centres had the genetic background (ST8-MRSA-IV) of the American lineages USA300 and USA500, thus demonstrating the diffusion of these strains in a population considered at risk for hospital associated infections.
  
  
  CONCLUSIONS
  Known MRSA epidemic clones such as USA600, USA800, USA1100, and UK EMRSA-3 were described for the first time in Italy. The diffusion of MRSA strains with high pathogenic potential in the CF population suggests that analysis of the MRSA strains involved in pulmonary infections of these patients is needed.
authors.affiliation: Department of Sciences for Woman and Child's Health, University of Florence, Florence, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Cocchi
authors.forename: L
authors.initials: L
authors.lastname: Cariani
authors.forename: F
authors.initials: F
authors.lastname: Favari
authors.forename: A
authors.initials: A
authors.lastname: Lambiase
authors.forename: E
authors.initials: E
authors.lastname: Fiscarelli
authors.forename: F V
authors.initials: FV
authors.lastname: Gioffré
authors.forename: A
authors.initials: A
authors.lastname: d'Aprile
authors.forename: E
authors.initials: E
authors.lastname: Manso
authors.forename: G
authors.initials: G
authors.lastname: Taccetti
authors.forename: C
authors.initials: C
authors.lastname: Braggion
authors.forename: G
authors.initials: G
authors.lastname: Döring
authors.forename: M
authors.initials: M
authors.lastname: de Martino
authors.forename: S
authors.initials: S
authors.lastname: Campana
mesh_terms: D003550:Cystic Fibrosis / Q000150:complications* / Q000382:microbiology*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification; D013203:Staphylococcal Infections / Q000150:complications* / Q000453:epidemiology*