title: Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: the HARMONY collection.
abstract: We analyzed a representative sample of methicillin-resistant Staphylococcus aureus (MRSA) from 11 European countries (referred to as the HARMONY collection) using three molecular typing methods used within the HARMONY group to examine their usefulness for large, multicenter MRSA surveillance networks that use these different laboratory methodologies. MRSA isolates were collected based on their prevalence in each center and their genetic diversity, assessed by pulsed-field gel electrophoresis (PFGE). PFGE groupings (< or = 3 bands difference between patterns) were compared to those made by sequencing of the variable repeats in the protein A gene spa and clonal designations based on multilocus sequence typing (MLST), combined with PCR analysis of the staphylococcal chromosome cassette containing the mec genes involved in methicillin resistance (SCCmec). A high level of discrimination was achieved using each of the three methodologies, with discriminatory indices between 89.5% and 91.9% with overlapping 95% confidence intervals. There was also a high level of concordance of groupings made using each method. MLST/SCCmec typing distinguished 10 groups containing at least two isolates, and these correspond to the majority of nosocomial MRSA clones described in the literature. PFGE and spa typing resolved 34 and 31 subtypes, respectively, within these 10 MRSA clones, with each subtype differing only slightly from the most common pattern using each method. The HARMONY group has found that the methods used in this study differ in their availability and affordability to European centers involved in MRSA surveillance. Here, we demonstrate that the integration of such technologies is achievable, although common protocols (such as we have developed for PFGE) may also be important, as is the use of centralized Internet sites to facilitate data analysis. PFGE and spa-typing data from analysis of MRSA isolates from the many centers that have access to the relevant equipment can be compared to reference patterns/sequences, and clonal designations can be made. In the majority of cases, these will correspond to those made by the (more expensive) method of choice-MLST/SCCmec typing-and these alternative methods can therefore be used as frontline typing systems for multicenter surveillance of MRSA.
authors.affiliation: Laboratory of Hospital Infection, Centre for Infections, health Protection Agency, London, United Kingdom.
authors.forename: Barry D
authors.initials: BD
authors.lastname: Cookson
authors.forename: D Ashley
authors.initials: DA
authors.lastname: Robinson
authors.forename: Alastair B
authors.initials: AB
authors.lastname: Monk
authors.forename: Stephen
authors.initials: S
authors.lastname: Murchan
authors.forename: Ariane
authors.initials: A
authors.lastname: Deplano
authors.forename: Rafaël
authors.initials: R
authors.lastname: de Ryck
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Struelens
authors.forename: Christina
authors.initials: C
authors.lastname: Scheel
authors.forename: Vivian
authors.initials: V
authors.lastname: Fussing
authors.forename: Saara
authors.initials: S
authors.lastname: Salmenlinna
authors.forename: Jaana
authors.initials: J
authors.lastname: Vuopio-Varkila
authors.forename: Christina
authors.initials: C
authors.lastname: Cuny
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Witte
authors.forename: Panayotis T
authors.initials: PT
authors.lastname: Tassios
authors.forename: Nikolas J
authors.initials: NJ
authors.lastname: Legakis
authors.forename: Willem
authors.initials: W
authors.lastname: van Leeuwen
authors.forename: Alex
authors.initials: A
authors.lastname: van Belkum
authors.forename: Anna
authors.initials: A
authors.lastname: Vindel
authors.forename: Javier
authors.initials: J
authors.lastname: Garaizar
authors.forename: Sara
authors.initials: S
authors.lastname: Haeggman
authors.forename: Barbro
authors.initials: B
authors.lastname: Olsson-Liljequist
authors.forename: Ulrika
authors.initials: U
authors.lastname: Ransjo
authors.forename: Manica
authors.initials: M
authors.lastname: Muller-Premru
authors.forename: Waleria
authors.initials: W
authors.lastname: Hryniewicz
authors.forename: Angela
authors.initials: A
authors.lastname: Rossney
authors.forename: Brian
authors.initials: B
authors.lastname: O'Connell
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Short
authors.forename: Jonathan
authors.initials: J
authors.lastname: Thomas
authors.forename: Simon
authors.initials: S
authors.lastname: O'Hanlon
authors.forename: Mark C
authors.initials: MC
authors.lastname: Enright
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005060:Europe / Q000453:epidemiology; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011159:Population Surveillance; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013205:Staphylococcal Protein A / Q000235:genetics; D013211:Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D013205:Staphylococcal Protein A