title: Prevalence and properties of mecC methicillin-resistant Staphylococcus aureus (MRSA) in bovine bulk tank milk in Great Britain.
abstract: OBJECTIVE
  mecC methicillin-resistant Staphylococcus aureus (MRSA) represent a newly recognized form of MRSA, distinguished by the possession of a divergent mecA homologue, mecC. The first isolate to be identified came from bovine milk, but there are few data on the prevalence of mecC MRSA among dairy cattle. The aim of this study was to conduct a prevalence study of mecC MRSA among dairy farms in Great Britain.
  
  
  METHODS
  Test farms were randomly selected by random order generation and bulk tank samples were tested for the presence of mecC MRSA by broth enrichment and plating onto chromogenic agar. All MRSA isolated were screened by PCR for mecA and mecC, and mecC MRSA were further characterized by multilocus sequence typing, spa typing and antimicrobial susceptibility testing.
  
  
  RESULTS
  mecC MRSA were detected on 10 of 465 dairy farms sampled in England and Wales (prevalence 2.15%, 95% CI 1.17%-3.91%), but not from 625 farms sampled in Scotland (95% CI of prevalence 0%-0.61%). Seven isolates belonged to sequence type (ST) 425, while the other three belonged to clonal complex 130. Resistance to non-β-lactam antibiotics was uncommon. All 10 isolates produced a negative result by slide agglutination for penicillin-binding protein 2a. mecA MRSA ST398 was detected on one farm in England.
  
  
  CONCLUSIONS
  mecC MRSA is widely distributed among dairy farms in Great Britain, but this distribution is not uniform across the whole country. These results provide an important baseline dataset to monitor the epidemiology of this emerging form of MRSA.
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
authors.forename: G K
authors.initials: GK
authors.lastname: Paterson
authors.forename: F J E
authors.initials: FJ
authors.lastname: Morgan
authors.forename: E M
authors.initials: EM
authors.lastname: Harrison
authors.forename: S J
authors.initials: SJ
authors.lastname: Peacock
authors.forename: J
authors.initials: J
authors.lastname: Parkhill
authors.forename: R N
authors.initials: RN
authors.lastname: Zadoks
authors.forename: M A
authors.initials: MA
authors.lastname: Holmes
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques; D002417:Cattle; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005798:Genes, Bacterial; D005838:Genotype; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D015995:Prevalence; D017422:Sequence Analysis, DNA; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial
keywords: antibiotic resistance; bovine mastitis; molecular epidemiology