Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: the HARMONY collection.
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.
Cookson
Barry D
BD
Laboratory of Hospital Infection, Centre for Infections, health Protection Agency, London, United Kingdom.
Robinson
D Ashley
DA
Monk
Alastair B
AB
Murchan
Stephen
S
Deplano
Ariane
A
de Ryck
Rafaël
R
Struelens
Marc J
MJ
Scheel
Christina
C
Fussing
Vivian
V
Salmenlinna
Saara
S
Vuopio-Varkila
Jaana
J
Cuny
Christina
C
Witte
Wolfgang
W
Tassios
Panayotis T
PT
Legakis
Nikolas J
NJ
van Leeuwen
Willem
W
van Belkum
Alex
A
Vindel
Anna
A
Garaizar
Javier
J
Haeggman
Sara
S
Olsson-Liljequist
Barbro
B
Ransjo
Ulrika
U
Muller-Premru
Manica
M
Hryniewicz
Waleria
W
Rossney
Angela
A
O'Connell
Brian
B
Short
Benjamin D
BD
Thomas
Jonathan
J
O'Hanlon
Simon
S
Enright
Mark C
MC
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*
D000900:Anti-Bacterial Agents; D013205:Staphylococcal Protein A