title: Recent emergence of Staphylococcus aureus clonal complex 398 in human blood cultures.
abstract: BACKGROUND
  Recently, a clone of MRSA with clonal complex 398 (CC398) has emerged that is related to an extensive reservoir in animals, especially pigs and veal calves. It has been reported previously that methicillin-susceptible variants of CC398 circulate among humans at low frequency, and these have been isolated in a few cases of bloodstream infections (BSI). The purpose of this study was to determine the prevalence of S. aureus CC398 in blood cultures taken from patients in a geographic area with a high density of pigs.
  
  
  RESULTS
  In total, 612 consecutive episodes of S. aureus BSI diagnosed before and during the emergence of CC398 were included. Three strains (2 MSSA and 1 MRSA) that were isolated from bacteremic patients between 2010-2011 were positive in a CC398 specific PCR. There was a marked increase in prevalence of S. aureus CC398 BSI isolated between 2010-2011 compared to the combined collections that were isolated between 1996-1998 and 2002-2005 (3/157, 1.9% vs. 0/455, 0.0%; p = 0.017).
  
  
  CONCLUSIONS
  In conclusion, in an area with a relative high density of pigs, S. aureus CC398 was found as a cause of BSI in humans only recently. This indicates that S. aureus CC398 is able to cause invasive infections in humans and that the prevalence is rising. Careful monitoring of the evolution and epidemiology of S. aureus CC398 in animals and humans is therefore important.
authors.affiliation: Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, The Netherlands. everkade@amphia.nl
authors.forename: Erwin
authors.initials: E
authors.lastname: Verkade
authors.forename: Anneke M C
authors.initials: AM
authors.lastname: Bergmans
authors.forename: Andries E
authors.initials: AE
authors.lastname: Budding
authors.forename: Alex
authors.initials: A
authors.lastname: van Belkum
authors.forename: Paul
authors.initials: P
authors.lastname: Savelkoul
authors.forename: Anton G
authors.initials: AG
authors.lastname: Buiting
authors.forename: Jan
authors.initials: J
authors.lastname: Kluytmans
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*; D002999:Clone Cells; D021903:DNA, Ribosomal Spacer / Q000032:analysis* / Q000235:genetics; D004197:Disease Reservoirs; D005260:Female; D006801:Humans; D008297:Male; D008712:Methicillin / Q000627:therapeutic use; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D009426:Netherlands / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D021903:DNA, Ribosomal Spacer; D008712:Methicillin