title: Multiple-locus variable number tandem repeat analysis is superior to spa typing and sufficient to characterize MRSA for surveillance purposes.
abstract: OBJECTIVE
  Assess the best approach to type methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcal protein A (spa) typing, multiple-locus variable number tandem repeat analysis (MLVA) or both.
  
  
  METHODS
  Discriminatory power of spa typing and MLVA was determined using 20,771 MRSA isolates.
  
  
  RESULTS
  There were twice as many MLVA types (MTs) as spa types present in the collection. Among the top 70% of the isolates, 37 spa types and 139 MTs were found. MLVA diversity among the top-10 spa types was high (diversity index 0.96), while spa diversity among the top-10 MTs was much lower (diversity index 0.83). The probability that two MRSA isolates with the same spa type also had the same MT was low (Wallace's coefficient 0.27). By contrast, most MRSA isolates yielding the same MT also had the same spa type (Wallace's coefficient 0.90).
  
  
  CONCLUSIONS
  MLVA is superior to spa typing and will suffice to characterize MRSA isolates for surveillance.
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Thijs
authors.initials: T
authors.lastname: Bosch
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Gerlinde N
authors.initials: GN
authors.lastname: Pluister
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: van Luit
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Fabian
authors.initials: F
authors.lastname: Landman
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Marga
authors.initials: M
authors.lastname: van Santen-Verheuvel
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Corrie
authors.initials: C
authors.lastname: Schot
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Sandra
authors.initials: S
authors.lastname: Witteveen
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Kim
authors.initials: K
authors.lastname: van der Zwaluw
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Max E  O C
authors.initials: ME
authors.lastname: Heck
authors.affiliation: Laboratory for Infectious Diseases & Screening, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Leo M
authors.initials: LM
authors.lastname: Schouls
mesh_terms: D015373:Bacterial Typing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics*; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology / Q000379:methods*; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D013205:Staphylococcal Protein A / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D013205:Staphylococcal Protein A
keywords: MLVA; MRSA; Staphylococcus aureus; diversity; spa typing; surveillance