title: Dissemination of community-acquired methicillin-resistant Staphylococcus aureus clones in northern Norway: sequence types 8 and 80 predominate.
abstract: Increasing frequencies of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strain isolation have been reported from many countries. The overall prevalence of MRSA in Norway is still very low. MRSA isolates (n = 67) detected between 1995 and 2003 in northern Norway were analyzed by pulsed-field gel electrophoresis, multilocus sequence typing, and staphylococcal cassette chromosome mec (SCCmec) typing. Sixty-seven isolates were associated with 13 different sequence types. Two successful MRSA clones predominated. Sequence type 8 (ST8) (40%) and ST80 (19%) containing SCCmec type IV were detected in hospitals and communities in different geographic regions during a 7-year period. In general, there was a low level of antimicrobial resistance. Only 26% of the isolates were multiresistant. International epidemic clones were detected. The frequent findings of SCCmec type IV (91%) along with heterogeneous genetic backgrounds suggest a horizontal spread of SCCmec type IV among staphylococcal strains in parallel with the clonal spread of successful MRSA strains.
authors.affiliation: Department for Microbiology and Virology, Faculty of Medicine, Institute of Medical Biology, University of Tromsø, N-9037 Tromsø, Norway. annemh@fagmed.uit.no
authors.forename: Anne-Merethe
authors.initials: AM
authors.lastname: Hanssen
authors.forename: Aina
authors.initials: A
authors.lastname: Fossum
authors.forename: Jarle
authors.initials: J
authors.lastname: Mikalsen
authors.forename: Dag S
authors.initials: DS
authors.lastname: Halvorsen
authors.forename: Geir
authors.initials: G
authors.lastname: Bukholm
authors.forename: Johanna U Ericson
authors.initials: JU
authors.lastname: Sollid
mesh_terms: D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology / Q000379:methods; D009664:Norway / Q000453:epidemiology; D010802:Phylogeny; D012703:Serotyping; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*