title: Rapid increase of genetically diverse methicillin-resistant Staphylococcus aureus, Copenhagen, Denmark.
abstract: In Copenhagen, methicillin-resistant Staphylococcus aureus (MRSA) accounted for <15 isolates per year during 1980-2002. However, since 2003 an epidemic increase has been observed, with 33 MRSA cases in 2003 and 110 in 2004. We analyzed these 143 cases epidemiologically and characterized isolates by pulsed-field gel electrophoresis, Staphylococcus protein A (spa) typing, multilocus sequence typing, staphylococcal chromosome cassette (SCC) mec typing, and detection of Panton-Valentine leukocidin (PVL) genes. Seventy-one percent of cases were community-onset MRSA (CO-MRSA); of these, 36% had no identified risk factors. We identified 29 spa types (t) and 16 sequence types (STs) belonging to 8 clonal complexes and 3 ST singletons. The most common clonal types were t024/ST8-IV, t019/ST30-IV, t044/ST80-IV, and t008/ST8-IV (USA300). A total of 86% of isolates harbored SCCmec IV, and 44% had PVL. Skin and soft tissue infections dominated. CO-MRSA with diverse genetic backgrounds is rapidly emerging in a low MRSA prevalence area.
authors.affiliation: Hvidovre Hospital, Hvidovre, Denmark.
authors.forename: Mette Damkjaer
authors.initials: MD
authors.lastname: Bartels
authors.forename: Kit
authors.initials: K
authors.lastname: Boye
authors.forename: Anders
authors.initials: A
authors.lastname: Rhod Larsen
authors.forename: Robert
authors.initials: R
authors.lastname: Skov
authors.forename: Henrik
authors.initials: H
authors.lastname: Westh
mesh_terms: D021821:Communicable Diseases, Emerging / Q000235:genetics / Q000382:microbiology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000235:genetics; D003428:Cross Infection / Q000235:genetics; D003718:Denmark / Q000453:epidemiology; D019143:Evolution, Molecular; D014644:Genetic Variation / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics*; D010802:Phylogeny; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics*